diff --git a/python/cog/predictor.py b/python/cog/predictor.py
index b32757104a..ce392ee9fc 100644
--- a/python/cog/predictor.py
+++ b/python/cog/predictor.py
@@ -59,6 +59,7 @@
     CogFile,
     CogPath,
     CogSecret,
+    NoneType,
 ]