diff --git a/builder/index-parse.y b/builder/index-parse.y
index ffc3f50f8..6dba255c0 100644
--- a/builder/index-parse.y
+++ b/builder/index-parse.y
@@ -157,7 +157,8 @@ emptylines:
 void
 yyerror (YYLTYPE * yylloc, yyscan_t scanner, struct parse_context *context, const char *msg)
 {
-  int has_suffix = context->error_suffix != NULL && context->error_suffix[0] != 0;
+  const int has_suffix =
+    context->error_suffix != NULL && context->error_suffix[0] != 0;
 
   fprintf (stderr, "%s%s%s%ssyntax error at line %d: %s%s%s\n",
            context->progname ? context->progname : "",
diff --git a/builder/index-scan.l b/builder/index-scan.l
index 71259136d..d4db826c5 100644
--- a/builder/index-scan.l
+++ b/builder/index-scan.l
@@ -82,7 +82,7 @@ extern void scanner_destroy (yyscan_t scanner);
                       yylval->field->next = NULL;
                       yylval->field->key = strndup (yytext, i);
                       if (yytext[i] == '[') {
-                        size_t j = strcspn (yytext+i+1, "]");
+                        const size_t j = strcspn (yytext+i+1, "]");
                         yylval->field->subkey = strndup (yytext+i+1, j);
                         i += 1+j+1;
                       } else {
diff --git a/builder/pxzcat-c.c b/builder/pxzcat-c.c
index fa9f6bf27..33923b532 100644
--- a/builder/pxzcat-c.c
+++ b/builder/pxzcat-c.c
@@ -110,7 +110,7 @@ virt_builder_pxzcat (value inputfilev, value outputfilev)
 
   pid = fork ();
   if (pid == -1) {
-    int err = errno;
+    const int err = errno;
     close (fd);
     unix_error (err, (char *) "fork", Nothing);
   }
@@ -188,7 +188,7 @@ pxzcat (value filenamev, value outputfilev, unsigned nr_threads)
    */
   ofd = open (String_val (outputfilev), O_WRONLY|O_CREAT|O_NOCTTY, 0644);
   if (ofd == -1) {
-    int err = errno;
+    const int err = errno;
     close (fd);
     unix_error (err, (char *) "open", outputfilev);
   }
@@ -196,25 +196,25 @@ pxzcat (value filenamev, value outputfilev, unsigned nr_threads)
   guestfs_int_fadvise_random (ofd);
 
   if (ftruncate (ofd, 1) == -1) {
-    int err = errno;
+    const int err = errno;
     close (fd);
     unix_error (err, (char *) "ftruncate", outputfilev);
   }
 
   if (lseek (ofd, 0, SEEK_SET) == -1) {
-    int err = errno;
+    const int err = errno;
     close (fd);
     unix_error (err, (char *) "lseek", outputfilev);
   }
 
   if (write (ofd, "\0", 1) == -1) {
-    int err = errno;
+    const int err = errno;
     close (fd);
     unix_error (err, (char *) "write", outputfilev);
   }
 
   if (ftruncate (ofd, size) == -1) {
-    int err = errno;
+    const int err = errno;
     close (fd);
     unix_error (err, (char *) "ftruncate", outputfilev);
   }
diff --git a/builder/yajl-c.c b/builder/yajl-c.c
index 6b7594372..3c2402e42 100644
--- a/builder/yajl-c.c
+++ b/builder/yajl-c.c
@@ -49,7 +49,7 @@ convert_yajl_value (yajl_val val, int level)
     caml_invalid_argument ("too many levels of object/array nesting");
 
   if (YAJL_IS_OBJECT (val)) {
-    size_t len = YAJL_GET_OBJECT(val)->len;
+    const size_t len = YAJL_GET_OBJECT(val)->len;
     size_t i;
     rv = caml_alloc (1, 3);
     lv = caml_alloc_tuple (len);
@@ -63,7 +63,7 @@ convert_yajl_value (yajl_val val, int level)
     }
     Store_field (rv, 0, lv);
   } else if (YAJL_IS_ARRAY (val)) {
-    size_t len = YAJL_GET_ARRAY(val)->len;
+    const size_t len = YAJL_GET_ARRAY(val)->len;
     size_t i;
     rv = caml_alloc (1, 4);
     lv = caml_alloc_tuple (len);
diff --git a/cat/ls.c b/cat/ls.c
index 59cb914cf..282996f05 100644
--- a/cat/ls.c
+++ b/cat/ls.c
@@ -550,7 +550,7 @@ static int field;
 static void
 next_field (void)
 {
-  int c = csv ? ',' : ' ';
+  const int c = csv ? ',' : ' ';
 
   field++;
   if (field == 1) return;
@@ -643,7 +643,8 @@ static void
 output_int64_size (int64_t size)
 {
   char buf[LONGEST_HUMAN_READABLE];
-  int hopts = human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
+  const int hopts =
+    human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
   int r;
 
   next_field ();
diff --git a/daemon/augeas.c b/daemon/augeas.c
index ea1163f77..14cc0cf7c 100644
--- a/daemon/augeas.c
+++ b/daemon/augeas.c
@@ -31,7 +31,7 @@
 
 #define FPRINTF_AUGEAS_ERROR(aug,fs,...)                                \
   do {                                                                  \
-    int code = aug_error (aug);                                         \
+    const int code = aug_error (aug);                                   \
     if (code == AUG_ENOMEM)                                             \
       reply_with_error (fs ": augeas out of memory", ##__VA_ARGS__);    \
     else {                                                              \
diff --git a/daemon/available.c b/daemon/available.c
index 1d0f5a069..977c4dead 100644
--- a/daemon/available.c
+++ b/daemon/available.c
@@ -40,7 +40,7 @@ do_internal_feature_available (const char *group)
 
   for (i = 0; optgroups[i].group != NULL; ++i) {
     if (STREQ (group, optgroups[i].group)) {
-      int av = optgroups[i].available ();
+      const int av = optgroups[i].available ();
       return av ? 0 : 1;
     }
   }
@@ -122,7 +122,8 @@ filesystem_available (const char *filesystem)
 int
 do_filesystem_available (const char *filesystem)
 {
-  size_t i, len = strlen (filesystem);
+  size_t i;
+  const size_t len = strlen (filesystem);
   int r;
 
   for (i = 0; i < len; ++i) {
diff --git a/daemon/base64.c b/daemon/base64.c
index 3f7a63054..3468c3342 100644
--- a/daemon/base64.c
+++ b/daemon/base64.c
@@ -35,7 +35,7 @@ GUESTFSD_EXT_CMD(str_base64, base64);
 static int
 write_cb (void *fd_ptr, const void *buf, size_t len)
 {
-  int fd = *(int *)fd_ptr;
+  const int fd = *(int *)fd_ptr;
   return xwrite (fd, buf, len);
 }
 
diff --git a/daemon/btrfs.c b/daemon/btrfs.c
index 811194d37..711f7ebfb 100644
--- a/daemon/btrfs.c
+++ b/daemon/btrfs.c
@@ -152,8 +152,8 @@ do_mkfs_btrfs (char *const *devices,
                int leafsize, const char *label, const char *metadata,
                int nodesize, int sectorsize)
 {
-  size_t nr_devices = count_strings (devices);
-  size_t MAX_ARGS = nr_devices + 64;
+  const size_t nr_devices = count_strings (devices);
+  const size_t MAX_ARGS = nr_devices + 64;
   const char *argv[MAX_ARGS];
   size_t i = 0, j;
   int r;
@@ -500,7 +500,7 @@ do_btrfs_subvolume_list (const mountable_t *fs)
 
   guestfs_int_btrfssubvolume_list *ret = NULL;
 
-  size_t nr_subvolumes = count_strings (lines);
+  const size_t nr_subvolumes = count_strings (lines);
 
   ret = malloc (sizeof *ret);
   if (!ret) {
@@ -733,8 +733,8 @@ int
 do_btrfs_device_add (char *const *devices, const char *fs)
 {
   static int btrfs_device_add_needs_force = -1;
-  size_t nr_devices = count_strings (devices);
-  size_t MAX_ARGS = nr_devices + 8;
+  const size_t nr_devices = count_strings (devices);
+  const size_t MAX_ARGS = nr_devices + 8;
   const char *argv[MAX_ARGS];
   size_t i = 0, j;
   CLEANUP_FREE char *fs_buf = NULL;
@@ -781,12 +781,12 @@ do_btrfs_device_add (char *const *devices, const char *fs)
 int
 do_btrfs_device_delete (char *const *devices, const char *fs)
 {
-  size_t nr_devices = count_strings (devices);
+  const size_t nr_devices = count_strings (devices);
 
   if (nr_devices == 0)
     return 0;
 
-  size_t MAX_ARGS = nr_devices + 8;
+  const size_t MAX_ARGS = nr_devices + 8;
   const char *argv[MAX_ARGS];
   size_t i = 0, j;
   CLEANUP_FREE char *fs_buf = NULL;
@@ -882,7 +882,7 @@ btrfs_set_uuid (const char *device, const char *uuid)
 {
   CLEANUP_FREE char *err = NULL;
   int r;
-  int has_uuid_opts = test_btrfstune_uuid_opt ();
+  const int has_uuid_opts = test_btrfstune_uuid_opt ();
 
   if (has_uuid_opts <= 0)
     NOT_SUPPORTED (-1, "btrfs filesystems' UUID cannot be changed");
@@ -902,7 +902,7 @@ btrfs_set_uuid_random (const char *device)
 {
   CLEANUP_FREE char *err = NULL;
   int r;
-  int has_uuid_opts = test_btrfstune_uuid_opt ();
+  const int has_uuid_opts = test_btrfstune_uuid_opt ();
 
   if (has_uuid_opts <= 0)
     NOT_SUPPORTED (-1, "btrfs filesystems' UUID cannot be changed");
@@ -1353,7 +1353,7 @@ do_btrfs_qgroup_show (const char *path)
   const size_t MAX_ARGS = 64;
   const char *argv[MAX_ARGS];
   size_t i = 0;
-  int has_raw_opt = test_btrfs_qgroup_show_raw_opt ();
+  const int has_raw_opt = test_btrfs_qgroup_show_raw_opt ();
   CLEANUP_FREE char *path_buf = NULL;
   CLEANUP_FREE char *err = NULL;
   CLEANUP_FREE char *out = NULL;
@@ -1391,7 +1391,7 @@ do_btrfs_qgroup_show (const char *path)
    *  0/5        9249849344   9249849344
    *
    */
-  size_t nr_qgroups = count_strings (lines) - 2;
+  const size_t nr_qgroups = count_strings (lines) - 2;
   guestfs_int_btrfsqgroup_list *ret = NULL;
   ret = malloc (sizeof *ret);
   if (!ret) {
@@ -2124,7 +2124,7 @@ int
 do_btrfs_image (char *const *sources, const char *image,
 		int compresslevel)
 {
-  size_t nr_sources =  count_strings (sources);
+  const size_t nr_sources =  count_strings (sources);
   const size_t MAX_ARGS = 64 + nr_sources;
   const char *argv[MAX_ARGS];
   size_t i = 0, j;
@@ -2324,7 +2324,7 @@ btrfs_minimum_size (const char *path)
   CLEANUP_FREE char *buf = NULL, *err = NULL, *out = NULL;
   int64_t ret = 0;
   int r;
-  int min_size_supported = test_btrfs_min_dev_size ();
+  const int min_size_supported = test_btrfs_min_dev_size ();
 
   if (min_size_supported == -1)
     return -1;
diff --git a/daemon/cleanups.c b/daemon/cleanups.c
index 5293ff23d..092e493d7 100644
--- a/daemon/cleanups.c
+++ b/daemon/cleanups.c
@@ -55,7 +55,7 @@ cleanup_unlink_free (void *ptr)
 void
 cleanup_close (void *ptr)
 {
-  int fd = * (int *) ptr;
+  const int fd = * (int *) ptr;
 
   if (fd >= 0)
     close (fd);
diff --git a/daemon/command.c b/daemon/command.c
index 01df28ac7..5bd79dfc8 100644
--- a/daemon/command.c
+++ b/daemon/command.c
@@ -217,9 +217,10 @@ commandrvf (char **stdoutput, char **stderror, unsigned flags,
 {
   size_t so_size = 0, se_size = 0;
   int so_fd[2], se_fd[2];
-  unsigned flag_copy_stdin = flags & COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN;
-  int flag_copy_fd = (int) (flags & COMMAND_FLAG_FD_MASK);
-  unsigned flag_out_on_err = flags & COMMAND_FLAG_FOLD_STDOUT_ON_STDERR;
+  const unsigned flag_copy_stdin =
+    flags & COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN;
+  const int flag_copy_fd = (int) (flags & COMMAND_FLAG_FD_MASK);
+  const unsigned flag_out_on_err = flags & COMMAND_FLAG_FOLD_STDOUT_ON_STDERR;
   pid_t pid;
   int r, quit, i;
   fd_set rset, rset2;
diff --git a/daemon/copy.c b/daemon/copy.c
index 2a6720bef..4fbf599dc 100644
--- a/daemon/copy.c
+++ b/daemon/copy.c
@@ -48,7 +48,7 @@ copy (const char *src, const char *src_display,
       int flags,
       int64_t srcoffset, int64_t destoffset, int64_t size, int sparse)
 {
-  int64_t saved_size = size;
+  const int64_t saved_size = size;
   int src_fd, dest_fd;
   CLEANUP_FREE char *buf = NULL;
   size_t n;
diff --git a/daemon/daemon.h b/daemon/daemon.h
index 994b47a3a..771698156 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -377,7 +377,7 @@ is_zero (const char *buffer, size_t size)
 #define CHROOT_IN				\
   do {						\
     if (sysroot_len > 0) {                      \
-      int __old_errno = errno;			\
+      const int __old_errno = errno;            \
       if (chroot (sysroot) == -1)               \
         perror ("CHROOT_IN: sysroot");		\
       errno = __old_errno;			\
@@ -386,7 +386,7 @@ is_zero (const char *buffer, size_t size)
 #define CHROOT_OUT				\
   do {						\
     if (sysroot_len > 0) {                      \
-      int __old_errno = errno;			\
+      const int __old_errno = errno;            \
       if (chroot (".") == -1)			\
         perror ("CHROOT_OUT: .");               \
       errno = __old_errno;			\
@@ -414,7 +414,7 @@ is_zero (const char *buffer, size_t size)
 /* Calls reply_with_error, but includes the Augeas error details. */
 #define AUGEAS_ERROR(fs,...)                                            \
   do {                                                                  \
-    int code = aug_error (aug);                                         \
+    const int code = aug_error (aug);                                   \
     if (code == AUG_ENOMEM)                                             \
       reply_with_error (fs ": augeas out of memory", ##__VA_ARGS__);    \
     else {                                                              \
diff --git a/daemon/debug.c b/daemon/debug.c
index da4cfc8be..c646be754 100644
--- a/daemon/debug.c
+++ b/daemon/debug.c
@@ -436,7 +436,7 @@ debug_ldd (const char *subcmd, size_t argc, char *const *const argv)
 static char *
 debug_ls (const char *subcmd, size_t argc, char *const *const argv)
 {
-  size_t len = count_strings (argv);
+  const size_t len = count_strings (argv);
   CLEANUP_FREE const char **cargv = NULL;
   size_t i;
   int r;
@@ -469,7 +469,7 @@ debug_ls (const char *subcmd, size_t argc, char *const *const argv)
 static char *
 debug_ll (const char *subcmd, size_t argc, char *const *const argv)
 {
-  size_t len = count_strings (argv);
+  const size_t len = count_strings (argv);
   CLEANUP_FREE const char **cargv = NULL;
   size_t i;
   int r;
@@ -675,7 +675,7 @@ debug_spew (const char *subcmd, size_t argc, char *const *const argv)
 static int
 write_cb (void *fd_ptr, const void *buf, size_t len)
 {
-  int fd = *(int *)fd_ptr;
+  const int fd = *(int *)fd_ptr;
   return xwrite (fd, buf, len);
 }
 
@@ -900,7 +900,7 @@ do_debug_upload (const char *filename, int mode)
   int fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY|O_CLOEXEC, mode);
 
   if (fd == -1) {
-    int err = errno;
+    const int err = errno;
     cancel_receive ();
     errno = err;
     reply_with_perror ("%s", filename);
@@ -909,7 +909,7 @@ do_debug_upload (const char *filename, int mode)
 
   int r = receive_file (write_cb, &fd);
   if (r == -1) {		/* write error */
-    int err = errno;
+    const int err = errno;
     cancel_receive ();
     errno = err;
     reply_with_error ("write error: %s", filename);
@@ -972,7 +972,7 @@ do_internal_rhbz914931 (int count)
 
   r = receive_file (crash_cb, &count);
   if (r == -1) {		/* write error */
-    int err = errno;
+    const int err = errno;
     cancel_receive ();
     errno = err;
     reply_with_error ("write error");
diff --git a/daemon/fallocate.c b/daemon/fallocate.c
index f98babfb2..3b573a3ea 100644
--- a/daemon/fallocate.c
+++ b/daemon/fallocate.c
@@ -53,7 +53,7 @@ do_fallocate64 (const char *path, int64_t len)
   }
 
 #ifdef HAVE_POSIX_FALLOCATE
-  int err = posix_fallocate (fd, 0, len);
+  const int err = posix_fallocate (fd, 0, len);
   if (err != 0) {
     errno = err;
     reply_with_perror ("%s", path);
diff --git a/daemon/file.c b/daemon/file.c
index 35f41d3d0..1ef78e402 100644
--- a/daemon/file.c
+++ b/daemon/file.c
@@ -201,7 +201,7 @@ do_write_file (const char *path, const char *content, int size)
   /* Note content_len must be small because of the limits on protocol
    * message size.
    */
-  int content_len = (int) strlen (content);
+  const int content_len = (int) strlen (content);
 
   if (size == 0)
     size = content_len;
@@ -455,8 +455,8 @@ do_file (const char *path)
 {
   CLEANUP_FREE char *buf = NULL;
   const char *display_path = path;
-
-  int is_dev = STRPREFIX (path, "/dev/");
+  const int is_dev = STRPREFIX (path, "/dev/");
+  struct stat statbuf;
 
   if (!is_dev) {
     buf = sysroot_path (path);
@@ -469,7 +469,6 @@ do_file (const char *path)
     /* For non-dev, check this is a regular file, else just return the
      * file type as a string (RHBZ#582484).
      */
-    struct stat statbuf;
     if (lstat (path, &statbuf) == -1) {
       reply_with_perror ("lstat: %s", display_path);
       return NULL;
diff --git a/daemon/fill.c b/daemon/fill.c
index 2d19df5db..d4f0ab2b6 100644
--- a/daemon/fill.c
+++ b/daemon/fill.c
@@ -86,7 +86,7 @@ do_fill (int c, int len, const char *path)
 int
 do_fill_pattern (const char *pattern, int len, const char *path)
 {
-  size_t patlen = strlen (pattern);
+  const size_t patlen = strlen (pattern);
 
   if (patlen < 1) {
     reply_with_error ("pattern string must be non-empty");
@@ -97,7 +97,7 @@ do_fill_pattern (const char *pattern, int len, const char *path)
     reply_with_error ("%d: length is < 0", len);
     return -1;
   }
-  size_t len_sz = (size_t) len;
+  const size_t len_sz = (size_t) len;
 
   int fd;
   CHROOT_IN;
@@ -112,7 +112,7 @@ do_fill_pattern (const char *pattern, int len, const char *path)
   /* XXX This implementation won't be very efficient for large files. */
   size_t n = 0;
   while (n < len_sz) {
-    size_t wrlen = len_sz - n < patlen ? len_sz - n : patlen;
+    const size_t wrlen = len_sz - n < patlen ? len_sz - n : patlen;
     if (xwrite (fd, pattern, wrlen) == -1) {
       reply_with_perror ("write: %s", path);
       close (fd);
diff --git a/daemon/find.c b/daemon/find.c
index b47caa887..604d3bfb9 100644
--- a/daemon/find.c
+++ b/daemon/find.c
@@ -113,7 +113,7 @@ do_find0 (const char *dir)
    * we'll need to modify the code to handle it.  XXX
    */
   while ((r = input_to_nul (fp, str, GUESTFS_MAX_CHUNK_SIZE)) > 0) {
-    size_t len = strlen (str);
+    const size_t len = strlen (str);
     if (len <= sysrootdirlen)
       continue;
 
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 03d8f0abb..bd3f7de7c 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -424,7 +424,7 @@ char *
 sysroot_path (const char *path)
 {
   char *r;
-  size_t len = strlen (path) + sysroot_len + 1;
+  const size_t len = strlen (path) + sysroot_len + 1;
 
   r = malloc (len);
   if (r == NULL)
diff --git a/daemon/inotify.c b/daemon/inotify.c
index 277c94c1a..74c895b1d 100644
--- a/daemon/inotify.c
+++ b/daemon/inotify.c
@@ -364,7 +364,7 @@ do_inotify_files (void)
   }
 
   while (fgets (buf, sizeof buf, fp) != NULL) {
-    size_t len = strlen (buf);
+    const size_t len = strlen (buf);
 
     if (len > 0 && buf[len-1] == '\n')
       buf[len-1] = '\0';
diff --git a/daemon/lvm-filter.c b/daemon/lvm-filter.c
index 619523901..44045b3ef 100644
--- a/daemon/lvm-filter.c
+++ b/daemon/lvm-filter.c
@@ -251,7 +251,7 @@ make_filter_strings (char *const *devices)
      *   for whole block devices:
      *     "a|^/dev/sda$|", "a|^/dev/sda[0-9]|",
      */
-    size_t slen = strlen (devices[i]);
+    const size_t slen = strlen (devices[i]);
 
     if (add_sprintf (&ret, "a|^%s$|", devices[i]) == -1)
       return NULL;
diff --git a/daemon/lvm.c b/daemon/lvm.c
index d3892fe77..d4909adfb 100644
--- a/daemon/lvm.c
+++ b/daemon/lvm.c
@@ -255,7 +255,7 @@ do_lvs (void)
   char *out;
   CLEANUP_FREE char *err = NULL;
   int r;
-  int has_S = test_lvs_has_S_opt ();
+  const int has_S = test_lvs_has_S_opt ();
 
   if (has_S < 0)
     return NULL;
diff --git a/daemon/md.c b/daemon/md.c
index 66e695ab9..3f31529e2 100644
--- a/daemon/md.c
+++ b/daemon/md.c
@@ -132,7 +132,7 @@ do_md_create (const char *name, char *const *devices,
     return -1;
   }
 
-  size_t MAX_ARGS = nrdevices + 16;
+  const size_t MAX_ARGS = nrdevices + 16;
   const char *argv[MAX_ARGS];
   size_t i = 0;
 
@@ -231,7 +231,7 @@ do_list_md_devices (void)
   /* Look for directories under /sys/block matching md[0-9]*
    * As an additional check, we also make sure they have a md subdirectory.
    */
-  int err = glob (PREFIX "[0-9]*" SUFFIX, GLOB_ERR, glob_errfunc, &mds);
+  const int err = glob (PREFIX "[0-9]*" SUFFIX, GLOB_ERR, glob_errfunc, &mds);
   if (err == GLOB_NOSPACE) {
     reply_with_error ("glob: returned GLOB_NOSPACE: "
                       "rerun with LIBGUESTFS_DEBUG=1");
diff --git a/daemon/mkfs.c b/daemon/mkfs.c
index a0617a074..f7509bfcb 100644
--- a/daemon/mkfs.c
+++ b/daemon/mkfs.c
@@ -117,11 +117,11 @@ do_mkfs (const char *fstype, const char *device, int blocksize,
        * have to determine the block device sector size in order to do
        * this.
        */
-      int ss = do_blockdev_getss (device);
+      const int ss = do_blockdev_getss (device);
       if (ss == -1)
         return -1;
 
-      int sectors_per_cluster = blocksize / ss;
+      const int sectors_per_cluster = blocksize / ss;
       if (sectors_per_cluster < 1 || sectors_per_cluster > 128) {
         reply_with_error ("unsupported cluster size for %s filesystem (requested cluster size = %d, sector size = %d, trying sectors per cluster = %d)",
                           fstype, blocksize, ss, sectors_per_cluster);
diff --git a/daemon/mount.c b/daemon/mount.c
index 4c83403f5..f2aedfd11 100644
--- a/daemon/mount.c
+++ b/daemon/mount.c
@@ -351,8 +351,8 @@ compare_longest_first (const void *vp1, const void *vp2)
 {
   char * const *p1 = (char * const *) vp1;
   char * const *p2 = (char * const *) vp2;
-  int n1 = strlen (*p1);
-  int n2 = strlen (*p2);
+  const int n1 = strlen (*p1);
+  const int n2 = strlen (*p2);
   return n2 - n1;
 }
 
diff --git a/daemon/ntfsclone.c b/daemon/ntfsclone.c
index f04017c77..ac061e6ce 100644
--- a/daemon/ntfsclone.c
+++ b/daemon/ntfsclone.c
@@ -59,7 +59,7 @@ read_error_file (char *error_file)
 static int
 write_cb (void *fd_ptr, const void *buf, size_t len)
 {
-  int fd = *(int *)fd_ptr;
+  const int fd = *(int *)fd_ptr;
   return xwrite (fd, buf, len);
 }
 
diff --git a/daemon/parted.c b/daemon/parted.c
index 00ae424ad..68ca1b609 100644
--- a/daemon/parted.c
+++ b/daemon/parted.c
@@ -303,7 +303,7 @@ get_table_field (const char *line, int n)
     return NULL;
   }
 
-  size_t len = strcspn (p, ":;");
+  const size_t len = strcspn (p, ":;");
   char *q = strndup (p, len);
   if (q == NULL) {
     reply_with_perror ("strndup");
@@ -681,7 +681,7 @@ sgdisk_info_extract_field (const char *device, int partnum, const char *field,
     return NULL;
   }
 
-  int fieldlen = strlen (field);
+  const int fieldlen = strlen (field);
 
   /* Parse the output of sgdisk -i:
    * Partition GUID code: 21686148-6449-6E6F-744E-656564454649 (BIOS boot partition)
@@ -739,7 +739,7 @@ static char *
 extract_uuid (const char *value)
 {
   /* The value contains only valid GUID characters */
-  size_t value_len = strspn (value, "-0123456789ABCDEF");
+  const size_t value_len = strspn (value, "-0123456789ABCDEF");
 
   char *ret = malloc (value_len + 1);
   if (ret == NULL) {
diff --git a/daemon/proto.c b/daemon/proto.c
index 654dd3a0d..696aa2f09 100644
--- a/daemon/proto.c
+++ b/daemon/proto.c
@@ -593,8 +593,8 @@ send_chunk (const guestfs_chunk *chunk)
   xdr_u_int (&xdr, &len);
   xdr_destroy (&xdr);
 
-  int err = (xwrite (sock, lenbuf, 4) == 0
-             && xwrite (sock, buf, len) == 0 ? 0 : -1);
+  const int err = (xwrite (sock, lenbuf, 4) == 0
+                   && xwrite (sock, buf, len) == 0 ? 0 : -1);
   if (err)
     error (EXIT_FAILURE, 0, "send_chunk: write failed");
 
@@ -722,7 +722,7 @@ pulse_mode_end (void)
 void
 pulse_mode_cancel (void)
 {
-  int err = errno;              /* Function must preserve errno. */
+  const int err = errno;        /* Function must preserve errno. */
   struct itimerval it;
   struct sigaction act;
 
@@ -752,7 +752,7 @@ static void
 async_safe_send_pulse (int sig)
 {
   /* XDR is a RFC ... */
-  unsigned char msg[] = {
+  const unsigned char msg[] = {
     (GUESTFS_PROGRESS_FLAG & 0xff000000) >> 24,
     (GUESTFS_PROGRESS_FLAG & 0x00ff0000) >> 16,
     (GUESTFS_PROGRESS_FLAG & 0x0000ff00) >> 8,
diff --git a/daemon/tar.c b/daemon/tar.c
index 6d0403a40..c5d9524de 100644
--- a/daemon/tar.c
+++ b/daemon/tar.c
@@ -127,7 +127,7 @@ read_error_file (char *error_file)
 static int
 write_cb (void *fd_ptr, const void *buf, size_t len)
 {
-  int fd = *(int *)fd_ptr;
+  const int fd = *(int *)fd_ptr;
   return xwrite (fd, buf, len);
 }
 
diff --git a/daemon/tsk.c b/daemon/tsk.c
index 2d0ea832d..dd368d71a 100644
--- a/daemon/tsk.c
+++ b/daemon/tsk.c
@@ -56,7 +56,8 @@ do_internal_filesystem_walk (const mountable_t *mountable)
   int ret = -1;
   TSK_FS_INFO *fs = NULL;
   TSK_IMG_INFO *img = NULL;  /* Used internally by tsk_fs_dir_walk */
-  int flags = TSK_FS_DIR_WALK_FLAG_ALLOC | TSK_FS_DIR_WALK_FLAG_UNALLOC |
+  const int flags =
+    TSK_FS_DIR_WALK_FLAG_ALLOC | TSK_FS_DIR_WALK_FLAG_UNALLOC |
     TSK_FS_DIR_WALK_FLAG_RECURSE | TSK_FS_DIR_WALK_FLAG_NOORPHAN;
 
   ret = open_filesystem (mountable->device, &img, &fs);
diff --git a/daemon/upload.c b/daemon/upload.c
index aeb730666..f034627d4 100644
--- a/daemon/upload.c
+++ b/daemon/upload.c
@@ -186,7 +186,7 @@ do_download (const char *filename)
     }
     total = statbuf.st_size;
   } else {
-    int64_t size = do_blockdev_getsize64 (filename);
+    const int64_t size = do_blockdev_getsize64 (filename);
     if (size == -1) {
       /* do_blockdev_getsize64 has already sent a reply. */
       close (fd);
diff --git a/daemon/zero.c b/daemon/zero.c
index c54575350..1b2ddf75a 100644
--- a/daemon/zero.c
+++ b/daemon/zero.c
@@ -137,7 +137,7 @@ do_wipefs (const char *device)
 int
 do_zero_device (const char *device)
 {
-  int64_t ssize = do_blockdev_getsize64 (device);
+  const int64_t ssize = do_blockdev_getsize64 (device);
   if (ssize == -1)
     return -1;
   uint64_t size = (uint64_t) ssize;
diff --git a/df/output.c b/df/output.c
index b9bbcb6bd..eed7f384d 100644
--- a/df/output.c
+++ b/df/output.c
@@ -97,7 +97,8 @@ print_stat (FILE *fp,
   const char *cols[4];
   int64_t factor, v;
   float percent;
-  int hopts = human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
+  const int hopts =
+    human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
   size_t i, len;
   char *dev;
 
diff --git a/diff/diff.c b/diff/diff.c
index 72f197f6f..2ac71eb5e 100644
--- a/diff/diff.c
+++ b/diff/diff.c
@@ -510,7 +510,7 @@ visit_entry (const char *dir, const char *name,
   i = t->nr_files++;
   if (i >= t->allocated) {
     struct file *old_files = t->files;
-    size_t old_allocated = t->allocated;
+    const size_t old_allocated = t->allocated;
 
     /* Number of entries in an F15 guest was 111524, and in a
      * Windows guest was 10709.
@@ -561,7 +561,7 @@ diff_guests (struct tree *t1, struct tree *t2)
 
   while (i1 < end1 || i2 < end2) {
     if (i1 < end1 && i2 < end2) {
-      int comp = strcmp (i1->path, i2->path);
+      const int comp = strcmp (i1->path, i2->path);
 
       /* i1->path < i2->path.  i1 catches up with i2 (files deleted) */
       if (comp < 0) {
@@ -575,11 +575,11 @@ diff_guests (struct tree *t1, struct tree *t2)
       }
       /* Otherwise i1->path == i2->path, compare in detail. */
       else {
-        int st = compare_stats (i1, i2);
+        const int st = compare_stats (i1, i2);
         if (st != 0)
           changed (t1->g, i1, t2->g, i2, st, 0);
         else if (i1->csum && i2->csum) {
-          int cst = strcmp (i1->csum, i2->csum);
+          const int cst = strcmp (i1->csum, i2->csum);
           changed (t1->g, i1, t2->g, i2, 0, cst);
         }
         i1++;
@@ -824,7 +824,7 @@ static int field;
 static void
 next_field (void)
 {
-  int c = csv ? ',' : ' ';
+  const int c = csv ? ',' : ' ';
 
   field++;
   if (field == 1) return;
@@ -980,7 +980,8 @@ static void
 output_int64_size (int64_t size)
 {
   char buf[LONGEST_HUMAN_READABLE];
-  int hopts = human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
+  const int hopts =
+    human_round_to_nearest|human_autoscale|human_base_1024|human_SI;
   int r;
 
   next_field ();
diff --git a/erlang/erl-guestfs-proto.c b/erlang/erl-guestfs-proto.c
index 24295ef68..f82823697 100644
--- a/erlang/erl-guestfs-proto.c
+++ b/erlang/erl-guestfs-proto.c
@@ -163,8 +163,8 @@ write_reply (ETERM *term)
 int
 atom_equals (ETERM *atom, const char *name)
 {
-  size_t namelen = strlen (name);
-  size_t atomlen = ERL_ATOM_SIZE (atom);
+  const size_t namelen = strlen (name);
+  const size_t atomlen = ERL_ATOM_SIZE (atom);
   if (namelen != atomlen) return 0;
   return strncmp (ERL_ATOM_PTR (atom), name, atomlen) == 0;
 }
diff --git a/examples/mount-local.c b/examples/mount-local.c
index ce12ffe9b..f9b421283 100644
--- a/examples/mount-local.c
+++ b/examples/mount-local.c
@@ -141,7 +141,7 @@ main (int argc, char *argv[])
       /* Set a magic prompt.  We only know how to do this for bash. */
       p = strrchr (shell, '/');
       if (p && strcmp (p+1, "bash") == 0) {
-        size_t len = 64 + strlen (shell);
+        const size_t len = 64 + strlen (shell);
         char *buf;
 
         buf = malloc (len);
diff --git a/fish/copy.c b/fish/copy.c
index f522950a5..7472e6f2c 100644
--- a/fish/copy.c
+++ b/fish/copy.c
@@ -50,7 +50,7 @@ run_copy_in (const char *cmd, size_t argc, char *argv[])
   if (remote == NULL)
     return -1;
 
-  int nr_locals = argc-1;
+  const int nr_locals = argc-1;
 
   /* Upload each local one at a time using copy-in. */
   int i;
@@ -74,7 +74,7 @@ run_copy_out (const char *cmd, size_t argc, char *argv[])
 
   /* Local directory is always the last arg. */
   const char *local = argv[argc-1];
-  int nr_remotes = argc-1;
+  const int nr_remotes = argc-1;
 
   /* Download each remote one at a time using copy-out. */
   int i, r;
diff --git a/fish/destpaths.c b/fish/destpaths.c
index 868f5a42b..622c8d7d9 100644
--- a/fish/destpaths.c
+++ b/fish/destpaths.c
@@ -198,8 +198,10 @@ complete_dest_paths_generator (const char *text, int state)
                     if (dirents->val[i].ftyp == 'u'
                         || dirents->val[i].ftyp == 'l'
                         || dirents->val[i].ftyp == '?') {
-                      int is_dir = guestfs_is_dir_opts (g, words[nr_words].name,
-                        GUESTFS_IS_DIR_OPTS_FOLLOWSYMLINKS, 1, -1);
+                      const int is_dir =
+                        guestfs_is_dir_opts (g, words[nr_words].name,
+                                             GUESTFS_IS_DIR_OPTS_FOLLOWSYMLINKS,
+                                             1, -1);
                       words[nr_words].is_dir = is_dir;
                     } else
                       words[nr_words].is_dir = dirents->val[i].ftyp == 'd';
@@ -245,7 +247,7 @@ complete_dest_paths_generator (const char *text, int state)
     if (cic_var && STREQ (cic_var, "off"))
       cic = 0;
 
-    int matches =
+    const int matches =
       cic ? STRCASEEQLEN (word->name, text, len)
           : STREQLEN (word->name, text, len);
 
diff --git a/fish/fish.c b/fish/fish.c
index 2ce2039ce..302b52f44 100644
--- a/fish/fish.c
+++ b/fish/fish.c
@@ -666,7 +666,7 @@ static void
 script (int prompt)
 {
   char *buf;
-  int global_exit_on_error = !prompt;
+  const int global_exit_on_error = !prompt;
   int exit_on_error;
   struct parsed_command pcmd;
 
@@ -799,7 +799,7 @@ parse_command_line (char *buf, int *exit_on_error_rtn)
    * popen(3), read the result and execute it as guestfish commands.
    */
   if (buf[0] == '<' && buf[1] == '!') {
-    int r = execute_and_inline (&buf[2], *exit_on_error_rtn);
+    const int r = execute_and_inline (&buf[2], *exit_on_error_rtn);
     if (r == -1)
       pcmd.status = -1;
     else
@@ -1369,7 +1369,7 @@ parse_string_list (const char *str)
       }
 
       /* Grow the token to accommodate the fragment */
-      size_t tok_end = tok_len;
+      const size_t tok_end = tok_len;
       tok_len += end - p;
       char *tok_new = realloc (tok, tok_len + 1);
       if (NULL == tok_new) {
@@ -1542,7 +1542,7 @@ static char *
 decode_ps1 (const char *str)
 {
   char *ret;
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   size_t i, j;
 
   /* Result string is always smaller than the input string.  This will
@@ -1867,7 +1867,7 @@ file_in_heredoc (const char *endmarker)
 
   while (fgets (buffer, BUFSIZ, stdin) != NULL) {
     /* Look for "END"<EOF> or "END\n" in input. */
-    size_t blen = strlen (buffer);
+    const size_t blen = strlen (buffer);
     if (STREQLEN (buffer, endmarker, markerlen) &&
         (blen == markerlen ||
          (blen == markerlen+1 && buffer[markerlen] == '\n')))
diff --git a/fish/prep-boot.c b/fish/prep-boot.c
index 45a5a8f11..7a6150ed0 100644
--- a/fish/prep-boot.c
+++ b/fish/prep-boot.c
@@ -44,7 +44,7 @@ prep_postlaunch_bootroot (const char *filename, prep_data *data, const char *dev
   if (parse_size (data->params[3], &bootsize) == -1)
     prep_error (data, filename, _("could not parse boot size"));
 
-  int sector = guestfs_blockdev_getss (g, device);
+  const int sector = guestfs_blockdev_getss (g, device);
   if (sector == -1)
     prep_error (data, filename, _("failed to get sector size of disk: %s"),
                 guestfs_last_error (g));
@@ -94,7 +94,7 @@ prep_postlaunch_bootrootlv (const char *filename, prep_data *data, const char *d
   if (parse_size (data->params[4], &bootsize) == -1)
     prep_error (data, filename, _("could not parse boot size"));
 
-  int sector = guestfs_blockdev_getss (g, device);
+  const int sector = guestfs_blockdev_getss (g, device);
   if (sector == -1)
     prep_error (data, filename, _("failed to get sector size of disk: %s"),
                 guestfs_last_error (g));
diff --git a/fish/progress.c b/fish/progress.c
index f684a66d4..20c15eab4 100644
--- a/fish/progress.c
+++ b/fish/progress.c
@@ -332,7 +332,7 @@ progress_bar_set (struct progress_bar *bar,
       fprintf (fp, "%s --- ", spinner (bar, bar->count));
     }
     else if (ratio < 1) {
-      int percent = 100.0 * ratio;
+      const int percent = 100.0 * ratio;
       fprintf (fp, "%s%3d%% ", spinner (bar, bar->count), percent);
     }
     else {
@@ -351,7 +351,7 @@ progress_bar_set (struct progress_bar *bar,
     fputs (s_open, fp);
 
     if (!pulse_mode) {
-      size_t dots = ratio * (double) (cols - COLS_OVERHEAD);
+      const size_t dots = ratio * (double) (cols - COLS_OVERHEAD);
 
       for (i = 0; i < dots; ++i)
         fputs (s_dot, fp);
@@ -360,7 +360,7 @@ progress_bar_set (struct progress_bar *bar,
     }
     else {           /* "Pulse mode": the progress bar just pulses. */
       for (i = 0; i < cols - COLS_OVERHEAD; ++i) {
-        int cc = (bar->count * 3 - i) % (cols - COLS_OVERHEAD);
+        const int cc = (bar->count * 3 - i) % (cols - COLS_OVERHEAD);
         if (cc >= 0 && cc <= 3)
           fputs (s_dot, fp);
         else
@@ -376,21 +376,21 @@ progress_bar_set (struct progress_bar *bar,
     if (estimate >= 100.0 * 60.0 * 60.0 /* >= 100 hours */) {
       /* Display hours<h> */
       estimate /= 60. * 60.;
-      int hh = floor (estimate);
+      const int hh = floor (estimate);
       fprintf (fp, ">%dh", hh);
     } else if (estimate >= 100.0 * 60.0 /* >= 100 minutes */) {
       /* Display hours<h>minutes */
       estimate /= 60. * 60.;
-      int hh = floor (estimate);
+      const int hh = floor (estimate);
       double ignore;
-      int mm = floor (modf (estimate, &ignore) * 60.);
+      const int mm = floor (modf (estimate, &ignore) * 60.);
       fprintf (fp, "%02dh%02d", hh, mm);
     } else if (estimate >= 0.0) {
       /* Display minutes:seconds */
       estimate /= 60.;
-      int mm = floor (estimate);
+      const int mm = floor (estimate);
       double ignore;
-      int ss = floor (modf (estimate, &ignore) * 60.);
+      const int ss = floor (modf (estimate, &ignore) * 60.);
       fprintf (fp, "%02d:%02d", mm, ss);
     }
     else /* < 0 means estimate was not meaningful */
diff --git a/fish/supported.c b/fish/supported.c
index 4beb63f99..26b9a786e 100644
--- a/fish/supported.c
+++ b/fish/supported.c
@@ -47,14 +47,14 @@ run_supported (const char *cmd, size_t argc, char *argv[])
   size_t i;
   size_t len = 0;
   for (i = 0; groups[i] != NULL; ++i) {
-    size_t l = strlen (groups[i]);
+    const size_t l = strlen (groups[i]);
     if (l > len)
       len = l;
   }
 
   for (i = 0; groups[i] != NULL; ++i) {
     char *gg[] = { groups[i], NULL };
-    int r = guestfs_available (g, gg);
+    const int r = guestfs_available (g, gg);
     const char *str = r == 0 ? _("yes") : _("no");
 
     printf ("%*s %s\n", (int) len, groups[i], str);
diff --git a/fuse/guestmount.c b/fuse/guestmount.c
index 330805889..dccc7ba6d 100644
--- a/fuse/guestmount.c
+++ b/fuse/guestmount.c
@@ -53,7 +53,7 @@ static int write_pid_file (const char *pid_file, pid_t pid);
 static void
 fuse_opt_add_opt_escaped (char **opts, const char *opt)
 {
-  unsigned oldlen = *opts ? strlen(*opts) : 0;
+  const unsigned oldlen = *opts ? strlen(*opts) : 0;
   char *d = realloc (*opts, oldlen + 1 + strlen(opt) * 2 + 1);
 
   if (!d)
diff --git a/generator/daemon.ml b/generator/daemon.ml
index 31ca76435..d8dc9cfb2 100644
--- a/generator/daemon.ml
+++ b/generator/daemon.ml
@@ -118,7 +118,7 @@ and generate_daemon_actions () =
     }                                                                   \\
     (path_out) = device_name_translation ((path));                      \\
     if ((path_out) == NULL) {                                           \\
-      int err = errno;                                                  \\
+      const int err = errno;                                            \\
       cancel_stmt;                                                      \\
       errno = err;                                                      \\
       reply_with_perror (\"%%s: %%s\", __func__, path);                     \\
diff --git a/generator/lua.ml b/generator/lua.ml
index 53c207272..89a8afd48 100644
--- a/generator/lua.ml
+++ b/generator/lua.ml
@@ -643,7 +643,7 @@ get_handle (lua_State *L, int index)
 static char **
 get_string_list (lua_State *L, int index)
 {
-  size_t len = lua_objlen (L, index);
+  const size_t len = lua_objlen (L, index);
   size_t i;
   char **strs;
 
@@ -786,8 +786,7 @@ get_event_bitmask (lua_State *L, int index)
 static uint64_t
 get_event (lua_State *L, int index)
 {
-  int r = luaL_checkoption (L, index, NULL, event_all);
-
+  const int r = luaL_checkoption (L, index, NULL, event_all);
   return UINT64_C(1) << r;
 }
 
diff --git a/generator/ruby.ml b/generator/ruby.ml
index 0f71cccb2..fb0003bfe 100644
--- a/generator/ruby.ml
+++ b/generator/ruby.ml
@@ -295,7 +295,7 @@ delete_event_callback (VALUE gv, VALUE event_handlev)
 {
   guestfs_h *g;
   char key[64];
-  int eh = NUM2INT (event_handlev);
+  const int eh = NUM2INT (event_handlev);
   VALUE *root;
 
   Data_Get_Struct (gv, guestfs_h, g);
diff --git a/mllib/getopt-c.c b/mllib/getopt-c.c
index 2d1a47e85..29845f6a9 100644
--- a/mllib/getopt-c.c
+++ b/mllib/getopt-c.c
@@ -249,7 +249,7 @@ guestfs_int_mllib_getopt_parse (value argsv, value specsv, value anon_funv, valu
 
     for (j = 0; j < len; ++j) {
       const char *key = String_val (Field (keysv, j));
-      size_t key_len = strlen (key);
+      const size_t key_len = strlen (key);
       int has_arg = 0;
 
       /* We assume that the key is valid, with the checks done in the
diff --git a/mllib/progress-c.c b/mllib/progress-c.c
index 8e5efd368..9162e4fd2 100644
--- a/mllib/progress-c.c
+++ b/mllib/progress-c.c
@@ -61,7 +61,7 @@ guestfs_int_mllib_progress_bar_init (value machine_readablev)
   CAMLparam1 (machine_readablev);
   CAMLlocal1 (barv);
   struct progress_bar *bar;
-  int machine_readable = Bool_val (machine_readablev);
+  const int machine_readable = Bool_val (machine_readablev);
   unsigned flags = 0;
 
   /* XXX Have to do this to get nl_langinfo to work properly.  However
diff --git a/ocaml/guestfs-c.c b/ocaml/guestfs-c.c
index edb4646c4..16d57321c 100644
--- a/ocaml/guestfs-c.c
+++ b/ocaml/guestfs-c.c
@@ -256,7 +256,7 @@ guestfs_int_ocaml_delete_event_callback (value gv, value ehv)
 {
   CAMLparam2 (gv, ehv);
   char key[64];
-  int eh = Int_val (ehv);
+  const int eh = Int_val (ehv);
 
   guestfs_h *g = Guestfs_val (gv);
 
diff --git a/p2v/conversion.c b/p2v/conversion.c
index 155c4d24a..e8f57412b 100644
--- a/p2v/conversion.c
+++ b/p2v/conversion.c
@@ -197,7 +197,7 @@ start_conversion (struct config *config,
   int ret = -1;
   int status;
   size_t i, len;
-  size_t nr_disks = guestfs_int_count_strings (config->disks);
+  const size_t nr_disks = guestfs_int_count_strings (config->disks);
   time_t now;
   struct tm tm;
   CLEANUP_FREE struct data_conn *data_conns = NULL;
@@ -877,7 +877,7 @@ generate_libvirt_xml (struct config *config, struct data_conn *data_conns,
                         config->interfaces[i]) == -1)
             error (EXIT_FAILURE, errno, "asprintf");
           if (g_file_get_contents (mac_filename, &mac, NULL, NULL)) {
-            size_t len = strlen (mac);
+            const size_t len = strlen (mac);
 
             if (len > 0 && mac[len-1] == '\n')
               mac[len-1] = '\0';
diff --git a/p2v/miniexpect.c b/p2v/miniexpect.c
index caf498dc1..d5a7c6e5d 100644
--- a/p2v/miniexpect.c
+++ b/p2v/miniexpect.c
@@ -345,7 +345,7 @@ mexp_expect (mexp_h *h, const mexp_regexp *regexps, int *ovector, int ovecsize)
       assert (h->buffer != NULL);
 
       for (i = 0; regexps[i].r > 0; ++i) {
-        int options = regexps[i].options | PCRE_PARTIAL_SOFT;
+        const int options = regexps[i].options | PCRE_PARTIAL_SOFT;
 
         r = pcre_exec (regexps[i].re, regexps[i].extra,
                        h->buffer, (int)h->len, 0,
diff --git a/src/appliance.c b/src/appliance.c
index 5748af523..942ecae55 100644
--- a/src/appliance.c
+++ b/src/appliance.c
@@ -152,7 +152,7 @@ build_appliance (guestfs_h *g,
     return -1;
 
   if (r == 1) {
-    size_t len = strlen (path);
+    const size_t len = strlen (path);
     *kernel = safe_malloc (g, len + 6 /* "kernel" */ + 2);
     *initrd = safe_malloc (g, len + 6 /* "initrd" */ + 2);
     *appliance = safe_malloc (g, len + 4 /* "root" */ + 2);
@@ -168,7 +168,7 @@ build_appliance (guestfs_h *g,
     return -1;
 
   if (r == 1) {
-    size_t len = strlen (path);
+    const size_t len = strlen (path);
     *kernel = safe_malloc (g, len + strlen (kernel_name) + 2);
     *initrd = safe_malloc (g, len + strlen (initrd_name) + 2);
     sprintf (*kernel, "%s/%s", path, kernel_name);
@@ -272,11 +272,11 @@ run_supermin_build (guestfs_h *g,
   CLEANUP_CMD_CLOSE struct command *cmd = guestfs_int_new_command (g);
   int r;
 #if 0                           /* not supported in supermin 5 yet XXX */
-  uid_t uid = getuid ();
-  uid_t euid = geteuid ();
-  gid_t gid = getgid ();
-  gid_t egid = getegid ();
-  int pass_u_g_args = uid != euid || gid != egid;
+  const uid_t uid = getuid ();
+  const uid_t euid = geteuid ();
+  const gid_t gid = getgid ();
+  const gid_t egid = getegid ();
+  const int pass_u_g_args = uid != euid || gid != egid;
 #endif
 
   guestfs_int_cmd_add_arg (cmd, SUPERMIN);
diff --git a/src/conn-socket.c b/src/conn-socket.c
index 624342b3b..4e1f78141 100644
--- a/src/conn-socket.c
+++ b/src/conn-socket.c
@@ -142,7 +142,7 @@ read_data (guestfs_h *g, struct connection *connv, void *bufv, size_t len)
 {
   char *buf = bufv;
   struct connection_socket *conn = (struct connection_socket *) connv;
-  size_t original_len = len;
+  const size_t original_len = len;
 
   if (conn->daemon_sock == -1) {
     error (g, _("read_data: socket not connected"));
@@ -246,7 +246,7 @@ write_data (guestfs_h *g, struct connection *connv,
 {
   const char *buf = bufv;
   struct connection_socket *conn = (struct connection_socket *) connv;
-  size_t original_len = len;
+  const size_t original_len = len;
 
   if (conn->daemon_sock == -1) {
     error (g, _("write_data: socket not connected"));
diff --git a/src/copy-in-out.c b/src/copy-in-out.c
index 50831bec3..a4e39f8b3 100644
--- a/src/copy-in-out.c
+++ b/src/copy-in-out.c
@@ -42,7 +42,7 @@ guestfs_impl_copy_in (guestfs_h *g,
   int fd;
   int r;
   char fdbuf[64];
-  size_t buf_len = strlen (localpath) + 1;
+  const size_t buf_len = strlen (localpath) + 1;
   CLEANUP_FREE char *buf = safe_malloc (g, buf_len);
   const char *dirname, *basename;
   struct stat statbuf;
@@ -52,7 +52,7 @@ guestfs_impl_copy_in (guestfs_h *g,
     return -1;
   }
 
-  int remote_is_dir = guestfs_is_dir (g, remotedir);
+  const int remote_is_dir = guestfs_is_dir (g, remotedir);
   if (remote_is_dir == -1)
     return -1;
 
@@ -152,7 +152,7 @@ guestfs_impl_copy_out (guestfs_h *g,
 
   if (r == 1) {               /* is file */
     CLEANUP_FREE char *filename = NULL;
-    size_t buf_len = strlen (remotepath) + 1;
+    const size_t buf_len = strlen (remotepath) + 1;
     CLEANUP_FREE char *buf = safe_malloc (g, buf_len);
     const char *basename;
 
@@ -180,7 +180,7 @@ guestfs_impl_copy_out (guestfs_h *g,
       return -1;
     }
 
-    size_t buf_len = strlen (remotepath) + 1;
+    const size_t buf_len = strlen (remotepath) + 1;
     CLEANUP_FREE char *buf = safe_malloc (g, buf_len);
     const char *basename;
     if (split_path (g, buf, buf_len, remotepath, NULL, &basename) == -1)
diff --git a/src/drives.c b/src/drives.c
index 5e7eb1241..1e3b0af72 100644
--- a/src/drives.c
+++ b/src/drives.c
@@ -727,7 +727,7 @@ parse_servers (guestfs_h *g, char *const *strs,
                struct drive_server **servers_rtn)
 {
   size_t i;
-  size_t n = guestfs_int_count_strings (strs);
+  const size_t n = guestfs_int_count_strings (strs);
   struct drive_server *servers;
 
   if (n == 0) {
diff --git a/src/errors.c b/src/errors.c
index ee21dafd2..b1ef491e5 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -191,7 +191,7 @@ guestfs_int_perrorf (guestfs_h *g, const char *fs, ...)
 {
   va_list args;
   CLEANUP_FREE char *msg = NULL;
-  int errnum = errno;
+  const int errnum = errno;
   int err;
   char buf[256];
 
@@ -294,7 +294,7 @@ void
 guestfs_int_print_BufferIn (FILE *out, const char *buf, size_t buf_size)
 {
   size_t i;
-  size_t orig_size = buf_size;
+  const size_t orig_size = buf_size;
 
   if (buf_size > 256)
     buf_size = 256;
@@ -392,7 +392,7 @@ void
 guestfs_int_external_command_failed (guestfs_h *g, int status,
 				     const char *cmd_name, const char *extra)
 {
-  size_t len = 80 + strlen (cmd_name);
+  const size_t len = 80 + strlen (cmd_name);
   CLEANUP_FREE char *status_string = safe_malloc (g, len);
 
   guestfs_int_exit_status_to_string (status, cmd_name, status_string, len);
diff --git a/src/fuse.c b/src/fuse.c
index cb8274fea..01de3a9e9 100644
--- a/src/fuse.c
+++ b/src/fuse.c
@@ -628,7 +628,7 @@ mount_local_utimens (const char *path, const struct timespec ts[2])
 static int
 mount_local_open (const char *path, struct fuse_file_info *fi)
 {
-  int flags = fi->flags & O_ACCMODE;
+  const int flags = fi->flags & O_ACCMODE;
   DECL_G ();
   DEBUG_CALL ("%s, 0%o", path, (unsigned) fi->flags);
 
diff --git a/src/handle.c b/src/handle.c
index ee3c4d3b9..81a3cb1f2 100644
--- a/src/handle.c
+++ b/src/handle.c
@@ -302,7 +302,7 @@ static char *
 getenv_from_strings (const void *stringsv, const char *name)
 {
   char **strings = (char **) stringsv;
-  size_t len = strlen (name);
+  const size_t len = strlen (name);
   size_t i;
 
   for (i = 0; strings[i] != NULL; ++i)
@@ -796,7 +796,7 @@ char *
 guestfs_impl_get_backend_setting (guestfs_h *g, const char *name)
 {
   char **settings = g->backend_settings;
-  size_t namelen = strlen (name);
+  const size_t namelen = strlen (name);
   size_t i;
 
   if (settings == NULL)
@@ -820,7 +820,7 @@ int
 guestfs_impl_clear_backend_setting (guestfs_h *g, const char *name)
 {
   char **settings = g->backend_settings;
-  size_t namelen = strlen (name);
+  const size_t namelen = strlen (name);
   size_t i, j;
   int count = 0;
 
diff --git a/src/inspect-apps.c b/src/inspect-apps.c
index b8767c3c8..b377f57c7 100644
--- a/src/inspect-apps.c
+++ b/src/inspect-apps.c
@@ -844,7 +844,7 @@ list_applications_windows_from_path (guestfs_h *g,
    * http://nsis.sourceforge.net/Add_uninstall_information_to_Add/Remove_Programs#Optional_values
    */
   for (i = 0; i < children->len; ++i) {
-    int64_t child = children->val[i].hivex_node_h;
+    const int64_t child = children->val[i].hivex_node_h;
     int64_t value;
     CLEANUP_FREE char *name = NULL, *display_name = NULL, *version = NULL,
       *install_path = NULL, *publisher = NULL, *url = NULL, *comments = NULL;
diff --git a/src/inspect-fs-cd.c b/src/inspect-fs-cd.c
index d8373f651..bb28c0fc7 100644
--- a/src/inspect-fs-cd.c
+++ b/src/inspect-fs-cd.c
@@ -349,7 +349,7 @@ check_isolinux_installer_root (guestfs_h *g, struct inspect_fs *fs)
 static void
 trim_cr (char *str)
 {
-  size_t n = strlen (str);
+  const size_t n = strlen (str);
   if (n > 0 && str[n-1] == '\r')
     str[n-1] = '\0';
 }
@@ -357,7 +357,7 @@ trim_cr (char *str)
 static void
 trim_quot (char *str)
 {
-  size_t n = strlen (str);
+  const size_t n = strlen (str);
   if (n > 0 && str[n-1] == '"')
     str[n-1] = '\0';
 }
diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
index 0e798bda4..cc0e6b1a0 100644
--- a/src/inspect-fs-unix.c
+++ b/src/inspect-fs-unix.c
@@ -351,13 +351,13 @@ parse_lsb_release (guestfs_h *g, struct inspect_fs *fs, const char *filename)
     else if (fs->product_name == NULL &&
              (STRPREFIX (lines[i], "DISTRIB_DESCRIPTION=\"") ||
               STRPREFIX (lines[i], "DISTRIB_DESCRIPTION='"))) {
-      size_t len = strlen (lines[i]) - 21 - 1;
+      const size_t len = strlen (lines[i]) - 21 - 1;
       fs->product_name = safe_strndup (g, &lines[i][21], len);
       r = 1;
     }
     else if (fs->product_name == NULL &&
              STRPREFIX (lines[i], "DISTRIB_DESCRIPTION=")) {
-      size_t len = strlen (lines[i]) - 20;
+      const size_t len = strlen (lines[i]) - 20;
       fs->product_name = safe_strndup (g, &lines[i][20], len);
       r = 1;
     }
@@ -1227,11 +1227,11 @@ check_hostname_freebsd (guestfs_h *g, struct inspect_fs *fs)
   for (i = 0; lines[i] != NULL; ++i) {
     if (STRPREFIX (lines[i], "hostname=\"") ||
         STRPREFIX (lines[i], "hostname='")) {
-      size_t len = strlen (lines[i]) - 10 - 1;
+      const size_t len = strlen (lines[i]) - 10 - 1;
       fs->hostname = safe_strndup (g, &lines[i][10], len);
       break;
     } else if (STRPREFIX (lines[i], "hostname=")) {
-      size_t len = strlen (lines[i]) - 9;
+      const size_t len = strlen (lines[i]) - 9;
       fs->hostname = safe_strndup (g, &lines[i][9], len);
       break;
     }
@@ -1394,7 +1394,7 @@ add_fstab_entry (guestfs_h *g, struct inspect_fs *fs,
    * Note these are further filtered by guestfs_inspect_get_mountpoints
    * and guestfs_inspect_get_filesystems.
    */
-  size_t n = fs->nr_fstab + 1;
+  const size_t n = fs->nr_fstab + 1;
   struct inspect_fstab_entry *p;
 
   p = safe_realloc (g, fs->fstab, n * sizeof (struct inspect_fstab_entry));
@@ -1861,8 +1861,8 @@ resolve_fstab_device (guestfs_h *g, const char *spec, Hash_table *md_map,
      * prefixed with vtbd. IDE hard drives used to be prefixed with ad and now
      * are with ada.
      */
-    int disk_i = guestfs_int_parse_unsigned_int (g, disk);
-    int part_i = guestfs_int_parse_unsigned_int (g, part);
+    const int disk_i = guestfs_int_parse_unsigned_int (g, disk);
+    const int part_i = guestfs_int_parse_unsigned_int (g, part);
     free (type);
     free (disk);
     free (part);
@@ -1877,8 +1877,8 @@ resolve_fstab_device (guestfs_h *g, const char *spec, Hash_table *md_map,
      * numbered from 5 in Linux.  I have no idea what happens when you
      * have multiple "slices" (the FreeBSD term for MBR partitions).
      */
-    int disk_i = guestfs_int_parse_unsigned_int (g, disk);
-    int slice_i = guestfs_int_parse_unsigned_int (g, slice);
+    const int disk_i = guestfs_int_parse_unsigned_int (g, disk);
+    const int slice_i = guestfs_int_parse_unsigned_int (g, slice);
     int part_i = part[0] - 'a' /* counting from 0 */;
     free (type);
     free (disk);
@@ -1897,7 +1897,7 @@ resolve_fstab_device (guestfs_h *g, const char *spec, Hash_table *md_map,
   }
   else if ((os_type == OS_TYPE_NETBSD) &&
            match3 (g, spec, re_netbsd_dev, &type, &disk, &part)) {
-    int disk_i = guestfs_int_parse_unsigned_int (g, disk);
+    const int disk_i = guestfs_int_parse_unsigned_int (g, disk);
     int part_i = part[0] - 'a'; /* counting from 0 */
     free (type);
     free (disk);
@@ -1914,7 +1914,7 @@ resolve_fstab_device (guestfs_h *g, const char *spec, Hash_table *md_map,
   }
   else if ((os_type == OS_TYPE_OPENBSD) &&
            match3 (g, spec, re_openbsd_dev, &type, &disk, &part)) {
-    int disk_i = guestfs_int_parse_unsigned_int (g, disk);
+    const int disk_i = guestfs_int_parse_unsigned_int (g, disk);
     int part_i = part[0] - 'a'; /* counting from 0 */
     free (type);
     free (disk);
@@ -1940,7 +1940,7 @@ resolve_fstab_device (guestfs_h *g, const char *spec, Hash_table *md_map,
      * Turn the disk number into a letter-based identifier, so
      * we can resolve it easily.
      */
-    int disk_i = guestfs_int_parse_unsigned_int (g, disk);
+    const int disk_i = guestfs_int_parse_unsigned_int (g, disk);
     const char disk_as_letter[2] = { disk_i + 'a', 0 };
     r = resolve_fstab_device_xdev (g, type, disk_as_letter, part, &device);
     free (type);
diff --git a/src/inspect-fs-windows.c b/src/inspect-fs-windows.c
index 8399a904b..c139051d0 100644
--- a/src/inspect-fs-windows.c
+++ b/src/inspect-fs-windows.c
@@ -301,7 +301,7 @@ check_windows_software_registry (guestfs_h *g, struct inspect_fs *fs)
   values = guestfs_hivex_node_values (g, node);
 
   for (i = 0; i < values->len; ++i) {
-    int64_t value = values->val[i].hivex_value_h;
+    const int64_t value = values->val[i].hivex_value_h;
     CLEANUP_FREE char *key = guestfs_hivex_value_key (g, value);
     if (key == NULL)
       goto out;
@@ -313,7 +313,7 @@ check_windows_software_registry (guestfs_h *g, struct inspect_fs *fs)
     }
     else if (STRCASEEQ (key, "CurrentMajorVersionNumber")) {
       size_t vsize;
-      int64_t vtype = guestfs_hivex_value_type (g, value);
+      const int64_t vtype = guestfs_hivex_value_type (g, value);
       CLEANUP_FREE char *vbuf = guestfs_hivex_value_value (g, value, &vsize);
 
       if (vbuf == NULL)
@@ -331,7 +331,7 @@ check_windows_software_registry (guestfs_h *g, struct inspect_fs *fs)
     }
     else if (STRCASEEQ (key, "CurrentMinorVersionNumber")) {
       size_t vsize;
-      int64_t vtype = guestfs_hivex_value_type (g, value);
+      const int64_t vtype = guestfs_hivex_value_type (g, value);
       CLEANUP_FREE char *vbuf = guestfs_hivex_value_value (g, value, &vsize);
 
       if (vbuf == NULL)
@@ -471,7 +471,7 @@ check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs)
   fs->drive_mappings = safe_calloc (g, 2*count + 1, sizeof (char *));
 
   for (i = count = 0; i < values->len; ++i) {
-    int64_t v = values->val[i].hivex_value_h;
+    const int64_t v = values->val[i].hivex_value_h;
     CLEANUP_FREE char *key = guestfs_hivex_value_key (g, v);
     if (key == NULL)
       goto out;
@@ -525,7 +525,7 @@ check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs)
     goto out;
 
   for (i = 0; i < values2->len; ++i) {
-    int64_t v = values2->val[i].hivex_value_h;
+    const int64_t v = values2->val[i].hivex_value_h;
     CLEANUP_FREE char *key = guestfs_hivex_value_key (g, v);
     if (key == NULL)
       goto out;
@@ -752,11 +752,12 @@ utf16_to_utf8 (/* const */ char *input, size_t len)
   char *inp = input;
   char *outp = out;
 
-  size_t r = iconv (ic, (ICONV_CONST char **) &inp, &inlen, &outp, &outlen);
+  const size_t r =
+    iconv (ic, (ICONV_CONST char **) &inp, &inlen, &outp, &outlen);
   if (r == (size_t) -1) {
     if (errno == E2BIG) {
-      int err = errno;
-      size_t prev = outalloc;
+      const int err = errno;
+      const size_t prev = outalloc;
       /* Try again with a larger output buffer. */
       free (out);
       outalloc *= 2;
@@ -769,7 +770,7 @@ utf16_to_utf8 (/* const */ char *input, size_t len)
     }
     else {
       /* Else some conversion failure, eg. EILSEQ, EINVAL. */
-      int err = errno;
+      const int err = errno;
       iconv_close (ic);
       free (out);
       errno = err;
diff --git a/src/inspect-fs.c b/src/inspect-fs.c
index adda4abb1..5e5b00499 100644
--- a/src/inspect-fs.c
+++ b/src/inspect-fs.c
@@ -150,9 +150,9 @@ check_filesystem (guestfs_h *g, const char *mountable,
   fs->mountable = safe_strdup (g, mountable);
 
   /* Optimize some of the tests by avoiding multiple tests of the same thing. */
-  int is_dir_etc = guestfs_is_dir (g, "/etc") > 0;
-  int is_dir_bin = guestfs_is_dir (g, "/bin") > 0;
-  int is_dir_share = guestfs_is_dir (g, "/share") > 0;
+  const int is_dir_etc = guestfs_is_dir (g, "/etc") > 0;
+  const int is_dir_bin = guestfs_is_dir (g, "/bin") > 0;
+  const int is_dir_share = guestfs_is_dir (g, "/share") > 0;
 
   /* Grub /boot? */
   if (guestfs_is_file (g, "/grub/menu.lst") > 0 ||
@@ -324,7 +324,7 @@ check_filesystem (guestfs_h *g, const char *mountable,
 static void
 extend_fses (guestfs_h *g)
 {
-  size_t n = g->nr_fses + 1;
+  const size_t n = g->nr_fses + 1;
   struct inspect_fs *p;
 
   p = safe_realloc (g, g->fses, n * sizeof (struct inspect_fs));
@@ -412,7 +412,7 @@ int
 guestfs_int_parse_unsigned_int (guestfs_h *g, const char *str)
 {
   long ret;
-  int r = xstrtol (str, NULL, 10, &ret, "");
+  const int r = xstrtol (str, NULL, 10, &ret, "");
   if (r != LONGINT_OK) {
     error (g, _("could not parse integer in version number: %s"), str);
     return -1;
@@ -425,7 +425,7 @@ int
 guestfs_int_parse_unsigned_int_ignore_trailing (guestfs_h *g, const char *str)
 {
   long ret;
-  int r = xstrtol (str, NULL, 10, &ret, NULL);
+  const int r = xstrtol (str, NULL, 10, &ret, NULL);
   if (r != LONGINT_OK) {
     error (g, _("could not parse integer in version number: %s"), str);
     return -1;
diff --git a/src/launch.c b/src/launch.c
index 5e6d1aa84..78bf46d71 100644
--- a/src/launch.c
+++ b/src/launch.c
@@ -337,7 +337,7 @@ guestfs_int_appliance_command_line (guestfs_h *g, const char *appliance_dev,
     snprintf (root, sizeof root, " root=%s", appliance_dev);
 
   if (tcg) {
-    int lpj = guestfs_int_get_lpj (g);
+    const int lpj = guestfs_int_get_lpj (g);
     if (lpj > 0)
       snprintf (lpj_s, sizeof lpj_s, " lpj=%d", lpj);
   }
diff --git a/src/listfs.c b/src/listfs.c
index de3b6f57f..88446cc9f 100644
--- a/src/listfs.c
+++ b/src/listfs.c
@@ -44,9 +44,9 @@ guestfs_impl_list_filesystems (guestfs_h *g)
   DECLARE_STRINGSBUF (ret);
 
   const char *lvm2[] = { "lvm2", NULL };
-  int has_lvm2 = guestfs_feature_available (g, (char **) lvm2);
+  const int has_lvm2 = guestfs_feature_available (g, (char **) lvm2);
   const char *ldm[] = { "ldm", NULL };
-  int has_ldm = guestfs_feature_available (g, (char **) ldm);
+  const int has_ldm = guestfs_feature_available (g, (char **) ldm);
 
   CLEANUP_FREE_STRING_LIST char **devices = NULL;
   CLEANUP_FREE_STRING_LIST char **partitions = NULL;
@@ -169,7 +169,8 @@ check_with_vfs_type (guestfs_h *g, const char *device, struct stringsbuf *sb)
     if (vols == NULL)
       return -1;
 
-    int64_t default_volume = guestfs_btrfs_subvolume_get_default (g, device);
+    const int64_t default_volume =
+      guestfs_btrfs_subvolume_get_default (g, device);
 
     for (size_t i = 0; i < vols->len; i++) {
       struct guestfs_btrfssubvolume *this = &vols->val[i];
@@ -193,7 +194,7 @@ check_with_vfs_type (guestfs_h *g, const char *device, struct stringsbuf *sb)
      * for things which are members of some RAID or LVM set, most
      * importantly "LVM2_member" which is a PV.
      */
-    size_t n = strlen (vfs_type);
+    const size_t n = strlen (vfs_type);
     if (n >= 7 && STREQ (&vfs_type[n-7], "_member"))
       return 0;
 
diff --git a/src/match.c b/src/match.c
index 41cc5f94a..149495987 100644
--- a/src/match.c
+++ b/src/match.c
@@ -33,7 +33,7 @@
 int
 guestfs_int_match (guestfs_h *g, const char *str, const pcre *re)
 {
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   r = pcre_exec (re, NULL, str, len, 0, 0, vec, sizeof vec / sizeof vec[0]);
@@ -50,7 +50,7 @@ guestfs_int_match (guestfs_h *g, const char *str, const pcre *re)
 char *
 guestfs_int_match1 (guestfs_h *g, const char *str, const pcre *re)
 {
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   r = pcre_exec (re, NULL, str, len, 0, 0, vec, sizeof vec / sizeof vec[0]);
@@ -65,7 +65,7 @@ int
 guestfs_int_match2 (guestfs_h *g, const char *str, const pcre *re,
 		    char **ret1, char **ret2)
 {
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   r = pcre_exec (re, NULL, str, len, 0, 0, vec, 30);
@@ -86,7 +86,7 @@ int
 guestfs_int_match3 (guestfs_h *g, const char *str, const pcre *re,
 		    char **ret1, char **ret2, char **ret3)
 {
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   r = pcre_exec (re, NULL, str, len, 0, 0, vec, 30);
@@ -109,7 +109,7 @@ int
 guestfs_int_match4 (guestfs_h *g, const char *str, const pcre *re,
 		    char **ret1, char **ret2, char **ret3, char **ret4)
 {
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   r = pcre_exec (re, NULL, str, len, 0, 0, vec, 30);
@@ -135,7 +135,7 @@ guestfs_int_match6 (guestfs_h *g, const char *str, const pcre *re,
 		    char **ret1, char **ret2, char **ret3, char **ret4,
 		    char **ret5, char **ret6)
 {
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   r = pcre_exec (re, NULL, str, len, 0, 0, vec, 30);
diff --git a/src/osinfo.c b/src/osinfo.c
index f4e2c7193..5887b2a1f 100644
--- a/src/osinfo.c
+++ b/src/osinfo.c
@@ -438,7 +438,7 @@ parse_version (guestfs_h *g, xmlNodePtr node, struct osinfo *osinfo)
   content = (char *) xmlNodeGetContent (node);
   if (content) {
     struct version version;
-    int res = guestfs_int_version_from_x_y (g, &version, content);
+    const int res = guestfs_int_version_from_x_y (g, &version, content);
     if (res < 0)
       return -1;
     else if (res > 0) {
diff --git a/src/proto.c b/src/proto.c
index cbf868047..32992d295 100644
--- a/src/proto.c
+++ b/src/proto.c
@@ -251,7 +251,7 @@ guestfs_int_send (guestfs_h *g, int proc_nr,
   struct guestfs_message_header hdr;
   XDR xdr;
   uint32_t len;
-  int serial = g->msg_next_serial++;
+  const int serial = g->msg_next_serial++;
   ssize_t r;
   CLEANUP_FREE char *msg_out = NULL;
   size_t msg_out_size;
diff --git a/src/qemu.c b/src/qemu.c
index 844c3f04c..c51133859 100644
--- a/src/qemu.c
+++ b/src/qemu.c
@@ -355,7 +355,8 @@ guestfs_int_qemu_supports_virtio_scsi (guestfs_h *g, struct qemu_data *data,
 char *
 guestfs_int_qemu_escape_param (guestfs_h *g, const char *param)
 {
-  size_t i, len = strlen (param);
+  size_t i;
+  const size_t len = strlen (param);
   char *p, *ret;
 
   ret = p = safe_malloc (g, len*2 + 1); /* max length of escaped name*/
diff --git a/src/unit-tests.c b/src/unit-tests.c
index c754ddb60..06d4d2736 100644
--- a/src/unit-tests.c
+++ b/src/unit-tests.c
@@ -237,7 +237,7 @@ static void
 test_getumask (void)
 {
   guestfs_h *g;
-  int orig_umask = umask (0777);
+  const int orig_umask = umask (0777);
 
   g = guestfs_create ();
   assert (g);
diff --git a/src/utils.c b/src/utils.c
index a9d9ea90b..0b8962c0e 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -73,7 +73,7 @@ guestfs_int_count_strings (char *const *argv)
 char **
 guestfs_int_copy_string_list (char *const *argv)
 {
-  size_t n = guestfs_int_count_strings (argv);
+  const size_t n = guestfs_int_count_strings (argv);
   size_t i, j;
   char **ret;
 
@@ -166,7 +166,8 @@ guestfs_int_join_strings (const char *sep, char *const *argv)
 char **
 guestfs_int_split_string (char sep, const char *str)
 {
-  size_t i, n, c, len = strlen (str);
+  size_t i, n, c;
+  const size_t len = strlen (str);
   char reject[2] = { sep, '\0' };
   char **ret;
 
diff --git a/src/version.c b/src/version.c
index 6796c2651..60ffe1e89 100644
--- a/src/version.c
+++ b/src/version.c
@@ -132,7 +132,7 @@ version_from_x_y_or_x (guestfs_h *g, struct version *v, const char *str,
 
     return 1;
   } else if (allow_only_x) {
-    int  major_version = guestfs_int_parse_unsigned_int (g, str);
+    const int major_version = guestfs_int_parse_unsigned_int (g, str);
     if (major_version == -1)
       return -1;
 
diff --git a/tests/c-api/tests-main.c b/tests/c-api/tests-main.c
index e3af651dd..5db407e03 100644
--- a/tests/c-api/tests-main.c
+++ b/tests/c-api/tests-main.c
@@ -341,7 +341,7 @@ match_re (const char *str, const char *pattern)
   const char *err;
   int offset;
   pcre *re;
-  size_t len = strlen (str);
+  const size_t len = strlen (str);
   int vec[30], r;
 
   re = pcre_compile (pattern, 0, &err, &offset, NULL);
diff --git a/tests/mount-local/test-parallel-mount-local.c b/tests/mount-local/test-parallel-mount-local.c
index 873d20a99..37b2b3db1 100644
--- a/tests/mount-local/test-parallel-mount-local.c
+++ b/tests/mount-local/test-parallel-mount-local.c
@@ -277,7 +277,7 @@ start_thread (void *statevp)
 static void
 test_mountpoint (const char *mp)
 {
-  int nr_passes = 5 + (random () & 31);
+  const int nr_passes = 5 + (random () & 31);
   int pass;
   int ret = EXIT_FAILURE;
   FILE *fp;
diff --git a/utils/qemu-speed-test/qemu-speed-test.c b/utils/qemu-speed-test/qemu-speed-test.c
index f26d71c36..091959436 100644
--- a/utils/qemu-speed-test/qemu-speed-test.c
+++ b/utils/qemu-speed-test/qemu-speed-test.c
@@ -378,7 +378,8 @@ test_block_device (void)
   CLEANUP_FREE char **devices = NULL;
   char *r;
   const char *argv[4];
-  int t = max_time_override > 0 ? max_time_override : TEST_BLOCK_DEVICE_TIME;
+  const int t =
+    max_time_override > 0 ? max_time_override : TEST_BLOCK_DEVICE_TIME;
   char tbuf[64];
   int64_t bytes_written, bytes_read;
 
diff --git a/v2v/domainxml-c.c b/v2v/domainxml-c.c
index 06a93eb42..3b00cada4 100644
--- a/v2v/domainxml-c.c
+++ b/v2v/domainxml-c.c
@@ -240,7 +240,7 @@ v2v_dumpxml (value passwordv, value connv, value domnamev)
    * this is only appropriate for virt-v2v.  (RHBZ#1138586)
    */
   if (!is_test_uri) {
-    int state = get_dom_state (dom);
+    const int state = get_dom_state (dom);
 
     if (state == VIR_DOMAIN_RUNNING ||
         state == VIR_DOMAIN_BLOCKED ||
diff --git a/v2v/xml-c.c b/v2v/xml-c.c
index 0be5b0b63..0af3d8f11 100644
--- a/v2v/xml-c.c
+++ b/v2v/xml-c.c
@@ -239,7 +239,7 @@ v2v_xml_xpathobjptr_get_nodeptr (value xpathobjv, value iv)
 {
   CAMLparam2 (xpathobjv, iv);
   xmlXPathObjectPtr xpathobj = xpathobjptr_val (xpathobjv);
-  int i = Int_val (iv);
+  const int i = Int_val (iv);
 
   if (i < 0 || i >= xpathobj->nodesetval->nodeNr)
     caml_invalid_argument ("get_nodeptr: node number out of range");