diff --git a/cat/virt-filesystems.c b/cat/virt-filesystems.c
index 6e86bfc54..434a7b434 100644
--- a/cat/virt-filesystems.c
+++ b/cat/virt-filesystems.c
@@ -688,7 +688,7 @@ do_output_blockdevs (void)
   for (i = 0; devices[i] != NULL; ++i) {
     int64_t size = -1;
     CLEANUP_FREE_STRING_LIST char **parents = NULL;
-    CLEANUP_FREE char *dev;
+    CLEANUP_FREE char *dev = NULL;
 
     dev = guestfs_canonical_device_name (g, devices[i]);
     if (!dev)
diff --git a/daemon/augeas.c b/daemon/augeas.c
index d3fe7db62..17d5c299f 100644
--- a/daemon/augeas.c
+++ b/daemon/augeas.c
@@ -355,7 +355,7 @@ do_aug_ls (const char *path)
   if (STREQ (path, "/"))
     matches = do_aug_match ("/*");
   else {
-    CLEANUP_FREE char *buf;
+    CLEANUP_FREE char *buf = NULL;
 
     len += 3;			/* / * + terminating \0 */
     buf = malloc (len);
diff --git a/daemon/debug.c b/daemon/debug.c
index be2a6b8cd..dca6edb8d 100644
--- a/daemon/debug.c
+++ b/daemon/debug.c
@@ -325,7 +325,7 @@ debug_binaries (const char *subcmd, size_t argc, char *const *const argv)
 {
   int r;
   char *out;
-  CLEANUP_FREE char *err;
+  CLEANUP_FREE char *err = NULL;
   char cmd[256];
 
   snprintf (cmd, sizeof (cmd),
@@ -395,7 +395,7 @@ debug_ls (const char *subcmd, size_t argc, char *const *const argv)
   size_t i;
   int r;
   char *out;
-  CLEANUP_FREE char *err;
+  CLEANUP_FREE char *err = NULL;
 
   cargv[0] = str_ls;
   cargv[1] = "-a";
@@ -422,7 +422,7 @@ debug_ll (const char *subcmd, size_t argc, char *const *const argv)
   size_t i;
   int r;
   char *out;
-  CLEANUP_FREE char *err;
+  CLEANUP_FREE char *err = NULL;
 
   cargv[0] = str_ls;
   cargv[1] = "-la";
diff --git a/daemon/ext2.c b/daemon/ext2.c
index dac8e0094..a49014f49 100644
--- a/daemon/ext2.c
+++ b/daemon/ext2.c
@@ -649,9 +649,9 @@ char *
 do_get_e2attrs (const char *filename)
 {
   int r;
-  CLEANUP_FREE char *buf;
+  CLEANUP_FREE char *buf = NULL;
   char *out;
-  CLEANUP_FREE char *err;
+  CLEANUP_FREE char *err = NULL;
   size_t i, j;
 
   buf = sysroot_path (filename);
diff --git a/daemon/file.c b/daemon/file.c
index 9c29ec3bc..7f39e622a 100644
--- a/daemon/file.c
+++ b/daemon/file.c
@@ -492,7 +492,7 @@ do_file (const char *path)
   const char *flags = is_dev ? "-zbsL" : "-zb";
 
   char *out;
-  CLEANUP_FREE char *err;
+  CLEANUP_FREE char *err = NULL;
   int r = command (&out, &err, str_file, flags, path, NULL);
 
   if (r == -1) {
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index b55f88a58..195fda011 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -710,7 +710,7 @@ commandf (char **stdoutput, char **stderror, int flags, const char *name, ...)
 {
   va_list args;
   /* NB: Mustn't free the strings which are on the stack. */
-  CLEANUP_FREE const char **argv;
+  CLEANUP_FREE const char **argv = NULL;
   char *s;
   size_t i;
   int r;
@@ -754,7 +754,7 @@ int
 commandrf (char **stdoutput, char **stderror, int flags, const char *name, ...)
 {
   va_list args;
-  CLEANUP_FREE const char **argv;
+  CLEANUP_FREE const char **argv = NULL;
   char *s;
   int i, r;
 
diff --git a/daemon/initrd.c b/daemon/initrd.c
index e26d98468..ea34000d4 100644
--- a/daemon/initrd.c
+++ b/daemon/initrd.c
@@ -86,7 +86,7 @@ char *
 do_initrd_cat (const char *path, const char *filename, size_t *size_r)
 {
   char tmpdir[] = "/tmp/initrd-cat-XXXXXX";
-  CLEANUP_FREE char *cmd;
+  CLEANUP_FREE char *cmd = NULL;
   struct stat statbuf;
   int fd, r;
   char *ret = NULL;
diff --git a/daemon/ls.c b/daemon/ls.c
index 96e7bf287..d3689cdc8 100644
--- a/daemon/ls.c
+++ b/daemon/ls.c
@@ -131,7 +131,7 @@ do_llz (const char *path)
   int r;
   char *out;
   CLEANUP_FREE char *err = NULL;
-  CLEANUP_FREE char *spath;
+  CLEANUP_FREE char *spath = NULL;
 
   spath = sysroot_path (path);
   if (!spath) {
diff --git a/daemon/xattr.c b/daemon/xattr.c
index b0a818b2f..16a01a670 100644
--- a/daemon/xattr.c
+++ b/daemon/xattr.c
@@ -280,7 +280,7 @@ do_internal_lxattrlist (const char *path, char *const *names)
 
   for (k = 0; names[k] != NULL; ++k) {
     void *newptr;
-    CLEANUP_FREE char *pathname;
+    CLEANUP_FREE char *pathname = NULL;
 
     /* Be careful in this loop about which errors cause the whole call
      * to abort, and which errors allow us to continue processing
diff --git a/fish/copy.c b/fish/copy.c
index 477bfe986..07a36a2fc 100644
--- a/fish/copy.c
+++ b/fish/copy.c
@@ -217,7 +217,7 @@ run_copy_out (const char *cmd, size_t argc, char *argv[])
   /* Download each remote one at a time using tar-out. */
   int i, r;
   for (i = 0; i < nr_remotes; ++i) {
-    CLEANUP_FREE char *remote;
+    CLEANUP_FREE char *remote = NULL;
 
     /* Allow win:... prefix on remotes. */
     remote = win_prefix (argv[i]);
diff --git a/fish/inspect.c b/fish/inspect.c
index 12ceaa75a..801d8673d 100644
--- a/fish/inspect.c
+++ b/fish/inspect.c
@@ -161,7 +161,7 @@ print_inspect_prompt (void)
 {
   size_t i;
   CLEANUP_FREE char *name = NULL;
-  CLEANUP_FREE_STRING_LIST char **mountpoints;
+  CLEANUP_FREE_STRING_LIST char **mountpoints = NULL;
 
   name = guestfs_inspect_get_product_name (g, root);
   if (name && STRNEQ (name, "unknown"))
diff --git a/src/inspect-fs-unix.c b/src/inspect-fs-unix.c
index 6fa7c8c72..60b081dfa 100644
--- a/src/inspect-fs-unix.c
+++ b/src/inspect-fs-unix.c
@@ -892,7 +892,7 @@ check_fstab (guestfs_h *g, struct inspect_fs *fs)
   CLEANUP_FREE_STRING_LIST char **entries = NULL;
   char **entry;
   char augpath[256];
-  CLEANUP_HASH_FREE Hash_table *md_map;
+  CLEANUP_HASH_FREE Hash_table *md_map = NULL;
 
   /* Generate a map of MD device paths listed in /etc/mdadm.conf to MD device
    * paths in the guestfs appliance */
diff --git a/src/inspect-fs-windows.c b/src/inspect-fs-windows.c
index ba062eb83..4f4911221 100644
--- a/src/inspect-fs-windows.c
+++ b/src/inspect-fs-windows.c
@@ -480,7 +480,7 @@ check_windows_system_registry (guestfs_h *g, struct inspect_fs *fs)
     if (STRCASEEQLEN (key, "\\DosDevices\\", 12) &&
         c_isalpha (key[12]) && key[13] == ':') {
       /* Get the binary value.  Is it a fixed disk? */
-      CLEANUP_FREE char *blob;
+      CLEANUP_FREE char *blob = NULL;
       char *device;
       size_t len;
       int64_t type;
diff --git a/src/launch-libvirt.c b/src/launch-libvirt.c
index 8995d0461..23070683c 100644
--- a/src/launch-libvirt.c
+++ b/src/launch-libvirt.c
@@ -1621,7 +1621,7 @@ make_drive_priv (guestfs_h *g, struct drive *drv,
       drv_priv->format = drv->format ? safe_strdup (g, drv->format) : NULL;
     }
     else {
-      CLEANUP_FREE char *qemu_device;
+      CLEANUP_FREE char *qemu_device = NULL;
 
       drv_priv->real_src.protocol = drive_protocol_file;
       qemu_device = guestfs___drive_source_qemu_param (g, &drv->src);