diff --git a/client/clip_client/client.py b/client/clip_client/client.py
index ee4f5f697..7b1bf1e0e 100644
--- a/client/clip_client/client.py
+++ b/client/clip_client/client.py
@@ -192,7 +192,7 @@ def _get_post_payload(self, content, kwargs):
             total_docs=len(content) if hasattr(content, '__len__') else None,
         )
         if self._scheme == 'grpc' and self._authorization:
-            payload.update(metadata=('Authorization', self._authorization))
+            payload.update(metadata=('authorization', self._authorization))
         elif self._scheme == 'http' and self._authorization:
             payload.update(headers={'Authorization': self._authorization})
         return payload
@@ -373,7 +373,7 @@ def _get_rank_payload(self, content, kwargs):
             total_docs=len(content) if hasattr(content, '__len__') else None,
         )
         if self._scheme == 'grpc' and self._authorization:
-            payload.update(metadata=('Authorization', self._authorization))
+            payload.update(metadata=('authorization', self._authorization))
         elif self._scheme == 'http' and self._authorization:
             payload.update(headers={'Authorization': self._authorization})
         return payload