diff --git a/src/strands/session/s3_session_manager.py b/src/strands/session/s3_session_manager.py
index 8d557e81c..a28cad8dd 100644
--- a/src/strands/session/s3_session_manager.py
+++ b/src/strands/session/s3_session_manager.py
@@ -95,7 +95,9 @@ def _get_session_path(self, session_id: str) -> str:
             ValueError: If session id contains a path separator.
         """
         session_id = _identifier.validate(session_id, _identifier.Identifier.SESSION)
-        return f"{self.prefix}/{SESSION_PREFIX}{session_id}/"
+        if self.prefix:
+            return f"{self.prefix}/{SESSION_PREFIX}{session_id}/"
+        return f"{SESSION_PREFIX}{session_id}/"
 
     def _get_agent_path(self, session_id: str, agent_id: str) -> str:
         """Get agent S3 prefix.