1 files changed, 1 insertions, 1 deletions
diff --git a/runtest.py b/runtest.py
index be94a35..964b441 100644
--- a/runtest.py
+++ b/runtest.py
@@ -495,7 +495,7 @@ class Unbuffered:
 sys.stdout = Unbuffered(sys.stdout)
 
 for t in tests:
-    t.command_args = [python]
+    t.command_args = [python, '-tt']
     if debug:
         t.command_args.append(debug)
     t.command_args.append(t.abspath)