diff --git a/src/services/adk/agent_builder.py b/src/services/adk/agent_builder.py
index c461bafd..e99eaba0 100644
--- a/src/services/adk/agent_builder.py
+++ b/src/services/adk/agent_builder.py
@@ -214,7 +214,7 @@ class AgentBuilder:
             else:
                 raise ValueError(f"Invalid agent type: {agent.type}")
 
-            sub_agents.append(sub_agent)
+            sub_agents.append((sub_agent, exit_stack))
             logger.info(f"Sub-agent added: {agent.name}")
 
         logger.info(f"Sub-agents created: {len(sub_agents)}")