diff --git a/src/defrag.c b/src/defrag.c
index 6b68f09bed..0051eaa317 100644
--- a/src/defrag.c
+++ b/src/defrag.c
@@ -2121,6 +2121,7 @@ static int DefragTimeoutTest(void)
 
     FAIL_IF(tracker->id != 99);
 
+    SCMutexUnlock(&tracker->lock);
     SCFree(p);
 
     DefragDestroy();