diff --git a/gio/gsettingsschema.c b/gio/gsettingsschema.c
index 1282c10a1..feadfe3aa 100644
--- a/gio/gsettingsschema.c
+++ b/gio/gsettingsschema.c
@@ -360,6 +360,9 @@ initialise_schema_sources (void)
 
       try_prepend_data_dir (g_get_user_data_dir ());
 
+      if (!is_setuid && (path = g_getenv ("NIX_GSETTINGS_OVERRIDES_DIR")) != NULL)
+        try_prepend_dir (path);
+
       /* Disallow loading extra schemas if running as setuid, as that could
        * allow reading privileged files. */
       if (!is_setuid && (path = g_getenv ("GSETTINGS_SCHEMA_DIR")) != NULL)