diff --git a/runtests.py b/runtests.py
index 4b71d6d0a506a975f2e04416414ae8f12a9a019f..c3286fcf3ecf6404be5061fa3edda48273c3d639 100755
--- a/runtests.py
+++ b/runtests.py
@@ -2100,3 +2100,4 @@ if __name__ == '__main__':
         except PendingThreadsError:
             # normal program exit won't kill the threads, do it the hard way here
             flush_and_terminate(1)
+        sys.exit(1)