diff --git a/libs/langchain/langchain/output_parsers/openai_functions.py b/libs/langchain/langchain/output_parsers/openai_functions.py
index 51c485482d..78b3a989b4 100644
--- a/libs/langchain/langchain/output_parsers/openai_functions.py
+++ b/libs/langchain/langchain/output_parsers/openai_functions.py
@@ -130,7 +130,9 @@ class JsonKeyOutputFunctionsParser(JsonOutputFunctionsParser):
     """The name of the key to return."""
 
     def parse_result(self, result: List[Generation], *, partial: bool = False) -> Any:
-        res = super().parse_result(result)
+        res = super().parse_result(result, partial=partial)
+        if partial and res is None:
+            return None
         return res.get(self.key_name) if partial else res[self.key_name]