diff --git a/glib/gfileutils.c b/glib/gfileutils.c
index bc4bcf1f4..1768358fe 100644
--- a/glib/gfileutils.c
+++ b/glib/gfileutils.c
@@ -1318,8 +1318,8 @@ g_file_set_contents (const gchar  *filename,
  * to 7 characters to @filename.
  *
  * If the file didn’t exist before and is created, it will be given the
- * permissions from @mode. Otherwise, the permissions of the existing file may
- * be changed to @mode depending on @flags, or they may remain unchanged.
+ * permissions from @mode. Otherwise, the permissions of the existing file will
+ * remain unchanged.
  *
  * Returns: %TRUE on success, %FALSE if an error occurred
  *
@@ -1362,6 +1362,7 @@ g_file_set_contents_full (const gchar            *filename,
       gboolean retval;
       int fd;
       gboolean do_fsync;
+      GStatBuf old_stat;
 
       tmp_filename = g_strdup_printf ("%s.XXXXXX", filename);
 
@@ -1379,6 +1380,26 @@ g_file_set_contents_full (const gchar            *filename,
           goto consistent_out;
         }
 
+      /* Maintain the permissions of the file if it exists */
+      if (!g_stat (filename, &old_stat))
+        {
+#ifndef G_OS_WIN32
+          if (fchmod (fd, old_stat.st_mode))
+#else  /* G_OS_WIN32 */
+          if (chmod (tmp_filename, old_stat.st_mode))
+#endif /* G_OS_WIN32 */
+            {
+              int saved_errno = errno;
+              if (error)
+                set_file_error (error,
+                                tmp_filename, _ ("Failed to set permissions of “%s”: %s"),
+                                saved_errno);
+              g_unlink (tmp_filename);
+              retval = FALSE;
+              goto consistent_out;
+            }
+        }
+
       do_fsync = fd_should_be_fsynced (fd, filename, flags);
       if (!write_to_file (contents, length, g_steal_fd (&fd), tmp_filename, do_fsync, error))
         {
diff --git a/glib/tests/fileutils.c b/glib/tests/fileutils.c
index fdc9ce3de..57e0a6f2e 100644
--- a/glib/tests/fileutils.c
+++ b/glib/tests/fileutils.c
@@ -1687,7 +1687,9 @@ test_set_contents_full (void)
           EXISTING_FILE_DIRECTORY,
         }
       existing_file;
-      int new_mode;  /* only relevant if @existing_file is %EXISTING_FILE_NONE */
+      /* only relevant if @existing_file is
+       * %EXISTING_FILE_NONE or %EXISTING_FILE_REGULAR */
+      int mode;
       gboolean use_strlen;
 
       gboolean expected_success;
@@ -1698,6 +1700,8 @@ test_set_contents_full (void)
       { EXISTING_FILE_NONE, 0644, FALSE, TRUE, 0 },
       { EXISTING_FILE_NONE, 0644, TRUE, TRUE, 0 },
       { EXISTING_FILE_NONE, 0600, FALSE, TRUE, 0 },
+      // Assume umask is 022, ensures that we preserve perms with, eg. 077
+      { EXISTING_FILE_REGULAR, 0666, FALSE, TRUE, 0 },
       { EXISTING_FILE_REGULAR, 0644, FALSE, TRUE, 0 },
 #ifndef G_OS_WIN32
       { EXISTING_FILE_SYMLINK, 0644, FALSE, TRUE, 0 },
@@ -1742,6 +1746,8 @@ test_set_contents_full (void)
                 g_assert_no_errno (g_fsync (fd));
                 close (fd);
 
+                g_assert_no_errno (chmod (file_name, tests[i].mode));
+
 #ifndef G_OS_WIN32
                 /* Pass an existing symlink to g_file_set_contents_full() to see
                  * what it does. */
@@ -1785,7 +1791,7 @@ test_set_contents_full (void)
           /* Set the file contents */
           ret = g_file_set_contents_full (set_contents_name, "b",
                                           tests[i].use_strlen ? -1 : 1,
-                                          flags, tests[i].new_mode, &error);
+                                          flags, tests[i].mode, &error);
 
           if (!tests[i].expected_success)
             {
@@ -1809,10 +1815,10 @@ test_set_contents_full (void)
 
               g_assert_no_errno (g_lstat (set_contents_name, &statbuf));
 
-              if (tests[i].existing_file == EXISTING_FILE_NONE)
+              if (tests[i].existing_file & (EXISTING_FILE_NONE | EXISTING_FILE_REGULAR))
                 {
                   int mode = statbuf.st_mode & ~S_IFMT;
-                  int new_mode = tests[i].new_mode;
+                  int new_mode = tests[i].mode;
 #ifdef G_OS_WIN32
                   /* on windows, group and others perms handling is different */
                   /* only check the rwx user permissions */