diff --git a/validate/gst/validate/gst-validate-pipeline-monitor.c b/validate/gst/validate/gst-validate-pipeline-monitor.c
index 5b8ef5d87c..ef686a1759 100644
--- a/validate/gst/validate/gst-validate-pipeline-monitor.c
+++ b/validate/gst/validate/gst-validate-pipeline-monitor.c
@@ -273,6 +273,7 @@ _find_structure_incompatible_fields (GQuark field_id, const GValue * value,
   if (gst_value_intersect (&intersect, value, filter_value)) {
     g_value_reset (&intersect);
     g_free (value_str);
+    g_free (filter_str);
 
     return TRUE;
   }