diff --git a/litellm/proxy/agent_endpoints/a2a_endpoints.py b/litellm/proxy/agent_endpoints/a2a_endpoints.py
index 5e5e43e2da2..b63afe536e1 100644
--- a/litellm/proxy/agent_endpoints/a2a_endpoints.py
+++ b/litellm/proxy/agent_endpoints/a2a_endpoints.py
@@ -174,13 +174,16 @@ async def _resolve_backend_auth_header(
 
 
 # Headers the proxy mints itself on the backend call. Forged client copies of
-# these must not be forwarded, but any other x-litellm-* header (e.g. an
-# admin-allowlisted x-litellm-api-key from extra_headers) is valid passthrough.
+# these must not be forwarded (agent-id is minted later in asend_message, where
+# agent_extra_headers would otherwise overwrite it), but any other x-litellm-*
+# header (e.g. an admin-allowlisted x-litellm-api-key from extra_headers) is
+# valid passthrough.
 _MINTED_A2A_IDENTITY_HEADERS: Final = frozenset(
     {
         AGENT_CALLER_USER_ID_HEADER.lower(),
         AGENT_CALLER_TEAM_ID_HEADER.lower(),
         "x-litellm-trace-id",
+        "x-litellm-agent-id",
     }
 )
 
diff --git a/tests/test_litellm/proxy/agent_endpoints/test_a2a_endpoints.py b/tests/test_litellm/proxy/agent_endpoints/test_a2a_endpoints.py
index ea1143a1d8e..2690bb88401 100644
--- a/tests/test_litellm/proxy/agent_endpoints/test_a2a_endpoints.py
+++ b/tests/test_litellm/proxy/agent_endpoints/test_a2a_endpoints.py
@@ -657,6 +657,7 @@ async def test_message_methods_forward_allowlisted_x_litellm_api_key(method: str
     mock_request.headers = {
         "x-litellm-api-key": "sk-allowlisted",
         "x-a2a-test-agent-x-litellm-team-id": "attacker-team",
+        "x-a2a-test-agent-x-litellm-agent-id": "attacker-agent",
     }
     user_api_key_dict = UserAPIKeyAuth(api_key="sk-test", user_id="real-user", team_id="real-team")
 
@@ -670,6 +671,9 @@ async def test_message_methods_forward_allowlisted_x_litellm_api_key(method: str
     assert forwarded_headers.get("X-LiteLLM-Team-Id") == "real-team", (
         "proxy-minted team id must not be overridden by a forged client header"
     )
+    assert "x-litellm-agent-id" not in {k.lower() for k in forwarded_headers}, (
+        "forged agent id must be stripped before asend_message mints the real one"
+    )
 
 
 @pytest.mark.asyncio