diff --git a/src/libnm-core-impl/tests/test-setting.c b/src/libnm-core-impl/tests/test-setting.c
index ab8de3a6b1..d6ac37b495 100644
--- a/src/libnm-core-impl/tests/test-setting.c
+++ b/src/libnm-core-impl/tests/test-setting.c
@@ -2952,7 +2952,7 @@ test_tc_config_tfilter_matchall_mirred(void)
     NMTCTfilter       *tfilter1;
     GError            *error      = NULL;
     gs_strfreev char **attr_names = NULL;
-    gs_free char      *str;
+    gs_free char      *str        = NULL;
     GVariant          *variant;
 
     tfilter1 =