diff --git a/pinecone/grpc/index_grpc.py b/pinecone/grpc/index_grpc.py
index dc9fad50d..02d8b3e2f 100644
--- a/pinecone/grpc/index_grpc.py
+++ b/pinecone/grpc/index_grpc.py
@@ -236,7 +236,7 @@ def _upsert_batch(
     def upsert_from_dataframe(
         self,
         df: Any,
-        namespace: str = "",
+        namespace: str | None = None,
         batch_size: int = 500,
         use_async_requests: bool = True,
         show_progress: bool = True,
diff --git a/pinecone/grpc/resources/vector_grpc.py b/pinecone/grpc/resources/vector_grpc.py
index 86629bc44..aa65ea653 100644
--- a/pinecone/grpc/resources/vector_grpc.py
+++ b/pinecone/grpc/resources/vector_grpc.py
@@ -174,7 +174,7 @@ def _upsert_batch(
     def upsert_from_dataframe(
         self,
         df,
-        namespace: str = "",
+        namespace: Optional[str] = None,
         batch_size: int = 500,
         use_async_requests: bool = True,
         show_progress: bool = True,