diff --git a/src/python/grpcio/grpc/__init__.py b/src/python/grpcio/grpc/__init__.py
index 513839df7d9..fb3900deccd 100644
--- a/src/python/grpcio/grpc/__init__.py
+++ b/src/python/grpcio/grpc/__init__.py
@@ -1078,7 +1078,7 @@ def access_token_call_credentials(access_token):
 
   Args:
     access_token: A string to place directly in the http request
-      authorization header, ie "Authorization: Bearer <access_token>".
+      authorization header, ie "authorization: Bearer <access_token>".
 
   Returns:
     A CallCredentials.