diff --git a/plugins/media-keys/gsd-media-keys-manager.c b/plugins/media-keys/gsd-media-keys-manager.c
index 1ad3f3df..5e2eb7e3 100644
--- a/plugins/media-keys/gsd-media-keys-manager.c
+++ b/plugins/media-keys/gsd-media-keys-manager.c
@@ -335,6 +335,7 @@ get_key_string (MediaKey *key)
 		return g_strdup_printf ("custom:%s", key->custom_path);
 	else
 		g_assert_not_reached ();
+                return NULL;
 }
 
 static char *
@@ -353,6 +354,7 @@ get_binding (GsdMediaKeysManager *manager,
 		return g_settings_get_string (settings, "binding");
 	} else
 		g_assert_not_reached ();
+                return NULL;
 }
 
 static void
diff --git a/plugins/rfkill/rfkill-glib.c b/plugins/rfkill/rfkill-glib.c
index 450e6533..6b2df693 100644
--- a/plugins/rfkill/rfkill-glib.c
+++ b/plugins/rfkill/rfkill-glib.c
@@ -254,6 +254,7 @@ op_to_string (unsigned int op)
 		return "CHANGE_ALL";
 	default:
 		g_assert_not_reached ();
+                return "NULL";
 	}
 }
 
diff --git a/plugins/xsettings/xsettings-manager.c b/plugins/xsettings/xsettings-manager.c
index 947cc9ee..18fbf599 100644
--- a/plugins/xsettings/xsettings-manager.c
+++ b/plugins/xsettings/xsettings-manager.c
@@ -269,6 +269,7 @@ xsettings_get_typecode (GVariant *value)
       return XSETTINGS_TYPE_COLOR;
     default:
       g_assert_not_reached ();
+      return NULL;
     }
 }