diff --git a/run_testcases_all.py b/run_testcases_all.py
index 5d88dd3..8b9091f 100644
--- a/run_testcases_all.py
+++ b/run_testcases_all.py
@@ -8,7 +8,7 @@ from unittest import TestSuite, TestLoader
 if __name__ == '__main__':
     import sys
 
-    if sys.stdin.isatty():
+    if sys.stderr.isatty():
         print('终端模式')
     else:
         print('GUI模式')