diff --git a/gio/tests/gdbus-peer.c b/gio/tests/gdbus-peer.c
index b410e80d1..dc4176cf2 100644
--- a/gio/tests/gdbus-peer.c
+++ b/gio/tests/gdbus-peer.c
@@ -1922,7 +1922,7 @@ main (int   argc,
   gint ret;
   GDBusNodeInfo *introspection_data = NULL;
 
-  g_test_init (&argc, &argv, NULL);
+  g_test_init (&argc, &argv, G_TEST_OPTION_ISOLATE_DIRS, NULL);
 
   introspection_data = g_dbus_node_info_new_for_xml (test_interface_introspection_xml, NULL);
   g_assert (introspection_data != NULL);