diff --git a/hubconf.py b/hubconf.py
index 2ebfd23de571b12b88b534a162bdfec7f87a0563..6e5807619621ec65903d68645bb75e3eafdf4147 100644
--- a/hubconf.py
+++ b/hubconf.py
@@ -20,17 +20,20 @@ import sys
 
 
 class _SysPathG(object):
+    def __init__(self, path):
+        self.path = path
+
     def __enter__(self, ):
-        sys.path.insert(0,
-                        os.path.join(
-                            os.path.dirname(os.path.abspath(__file__)),
-                            'ppcls', 'modeling'))
+        sys.path.insert(0, self.path)
 
     def __exit__(self, type, value, traceback):
-        sys.path.pop(0)
+        _p = sys.path.pop(0)
+        assert _p == self.path, 'make sure pop {} correctly.'.format(self.path)
 
 
-with _SysPathG():
+with _SysPathG(
+        os.path.join(
+            os.path.dirname(os.path.abspath(__file__)), 'ppcls', 'modeling')):
     import architectures
 
     def _load_pretrained_parameters(model, name):