diff --git a/sdk/python/kfp/components/_python_op.py b/sdk/python/kfp/components/_python_op.py
index c83d6e6682..54f780f5a0 100644
--- a/sdk/python/kfp/components/_python_op.py
+++ b/sdk/python/kfp/components/_python_op.py
@@ -247,7 +247,7 @@ def _strip_type_hints_using_lib2to3(source_code: str) -> str:
         def get_fixers(self):
             return self._fixers, []
 
-    stripped_code = Refactor([StripAnnotations]).refactor_string(source_code, '')
+    stripped_code = str(Refactor([StripAnnotations]).refactor_string(source_code, ''))
     return stripped_code