diff --git a/vertexai/agent_engines/templates/adk.py b/vertexai/agent_engines/templates/adk.py
index 7e21e6c680..feea1a6715 100644
--- a/vertexai/agent_engines/templates/adk.py
+++ b/vertexai/agent_engines/templates/adk.py
@@ -609,7 +609,7 @@ async def _init_session(
             session_state = {}
             for auth_id, auth in request.authorizations.items():
                 auth = _Authorization(**auth)
-                session_state[f"temp:{auth_id}"] = auth.access_token
+                session_state[auth_id] = auth.access_token
 
         if request.session_id:
             session_id = request.session_id
diff --git a/vertexai/preview/reasoning_engines/templates/adk.py b/vertexai/preview/reasoning_engines/templates/adk.py
index a3220228ac..07c3ee44c3 100644
--- a/vertexai/preview/reasoning_engines/templates/adk.py
+++ b/vertexai/preview/reasoning_engines/templates/adk.py
@@ -557,7 +557,7 @@ async def _init_session(
             session_state = {}
             for auth_id, auth in request.authorizations.items():
                 auth = _Authorization(**auth)
-                session_state[f"temp:{auth_id}"] = auth.access_token
+                session_state[auth_id] = auth.access_token
 
         if request.session_id:
             session_id = request.session_id