diff -u -N -r a/gio/gsettingsschema.c b/gio/gsettingsschema.c
--- a/gio/gsettingsschema.c	2014-02-12 21:08:36.000000000 +0100
+++ b/gio/gsettingsschema.c	2014-09-04 20:50:16.923420403 +0200
@@ -200,6 +200,9 @@
 GSettingsSchemaSource *
 g_settings_schema_source_ref (GSettingsSchemaSource *source)
 {
+  if (source == NULL)
+    g_error ("g_settings_schema_source_ref() called with source == NULL!");
+
   g_atomic_int_inc (&source->ref_count);
 
   return source;
@@ -216,6 +219,9 @@
 void
 g_settings_schema_source_unref (GSettingsSchemaSource *source)
 {
+  if (source == NULL)
+    g_error ("g_settings_schema_source_unref() called with source == NULL!");
+
   if (g_atomic_int_dec_and_test (&source->ref_count))
     {
       if (source == schema_sources)
diff -u -N -r a/gio/gsettings-tool.c b/gio/gsettings-tool.c
--- a/gio/gsettings-tool.c	2014-02-03 18:40:41.000000000 +0100
+++ b/gio/gsettings-tool.c	2014-09-04 21:09:40.306794238 +0200
@@ -674,6 +674,8 @@
   gchar *tmp;
 #endif
 
+  GSettingsSchemaSource * schema_source;
+
   setlocale (LC_ALL, "");
   textdomain (GETTEXT_PACKAGE);
 
@@ -692,7 +694,25 @@
   if (argc < 2)
     return gsettings_help (FALSE, NULL);
 
-  global_schema_source = g_settings_schema_source_ref (g_settings_schema_source_get_default ());
+  if (strcmp (argv[1], "help") == 0)
+    if (argc == 2)
+      return gsettings_help (TRUE, NULL);
+    else
+      return gsettings_help (TRUE, argv[2]);
+
+  if (argc == 2 && strcmp (argv[1], "--version") == 0)
+    {
+      gsettings_print_version();
+      return 0;
+    }
+
+  schema_source = g_settings_schema_source_get_default ();
+  if (schema_source == NULL)
+    {
+      g_printerr (_("No global schema source found!\n"));
+      return 1;
+    }
+  global_schema_source = g_settings_schema_source_ref (schema_source);
 
   if (argc > 3 && g_str_equal (argv[1], "--schemadir"))
     {
@@ -715,13 +735,7 @@
       argc -= 2;
     }
 
-  if (strcmp (argv[1], "help") == 0)
-    return gsettings_help (TRUE, argv[2]);
-
-  else if (argc == 2 && strcmp (argv[1], "--version") == 0)
-    function = gsettings_print_version;
-
-  else if (argc == 2 && strcmp (argv[1], "list-schemas") == 0)
+  if (argc == 2 && strcmp (argv[1], "list-schemas") == 0)
     function = gsettings_list_schemas;
 
   else if (argc == 2 && strcmp (argv[1], "list-relocatable-schemas") == 0)