diff --git a/qinling/utils/common.py b/qinling/utils/common.py
index 3fa9f8b5..e422984d 100644
--- a/qinling/utils/common.py
+++ b/qinling/utils/common.py
@@ -136,7 +136,7 @@ class ForkedPdb(pdb.Pdb):
     def interaction(self, *args, **kwargs):
         _stdin = sys.stdin
         try:
-            sys.stdin = file('/dev/stdin')
+            sys.stdin = open('/dev/stdin', 'r')
             pdb.Pdb.interaction(self, *args, **kwargs)
         finally:
             sys.stdin = _stdin