diff --git a/tests/conform/test-utils.c b/tests/conform/test-utils.c
index 651e4ef1b..b765b4697 100644
--- a/tests/conform/test-utils.c
+++ b/tests/conform/test-utils.c
@@ -24,7 +24,7 @@ test_utils_init (TestUtilsGTestFixture *fixture,
                 "$ make test-report");
   counter++;
 
-  setenv ("COGL_X11_SYNC", "1", 0);
+  g_setenv ("COGL_X11_SYNC", "1", 0);
 
   state->ctx = cogl_context_new (NULL, &error);
   if (!state->ctx)