diff --git a/daemon/base64.c b/daemon/base64.c
index 263c87ab2..04b29fd63 100644
--- a/daemon/base64.c
+++ b/daemon/base64.c
@@ -125,7 +125,7 @@ do_base64_out (const char *file)
   }
 
   /* Construct the command. */
-  if (asprintf_nowarn (&cmd, "%s %s", str_base64, buf) == -1) {
+  if (asprintf_nowarn (&cmd, "%s %Q", str_base64, buf) == -1) {
     reply_with_perror ("asprintf");
     return -1;
   }
diff --git a/daemon/tar.c b/daemon/tar.c
index 9bf85f57a..461e529ce 100644
--- a/daemon/tar.c
+++ b/daemon/tar.c
@@ -342,7 +342,7 @@ do_tar_out (const char *dir, const char *compress, int numericowner,
   }
 
   /* "tar -C /sysroot%s -cf - ." but we have to quote the dir. */
-  if (asprintf_nowarn (&cmd, "%s -C %s%s%s%s -cf - .",
+  if (asprintf_nowarn (&cmd, "%s -C %Q%s%s%s -cf - .",
                        str_tar,
                        buf, filter,
                        numericowner ? " --numeric-owner" : "",