diff --git a/src/mcp/server/auth/handlers/revoke.py b/src/mcp/server/auth/handlers/revoke.py
index 4efd154001..930ac8e99a 100644
--- a/src/mcp/server/auth/handlers/revoke.py
+++ b/src/mcp/server/auth/handlers/revoke.py
@@ -20,7 +20,7 @@ class RevocationRequest(BaseModel):
     token: str
     token_type_hint: Literal["access_token", "refresh_token"] | None = None
     client_id: str
-    client_secret: str | None
+    client_secret: str | None = None
 
 
 class RevocationErrorResponse(BaseModel):
diff --git a/tests/server/mcpserver/auth/test_auth_integration.py b/tests/server/mcpserver/auth/test_auth_integration.py
index e9c1df8465..b87b48a01b 100644
--- a/tests/server/mcpserver/auth/test_auth_integration.py
+++ b/tests/server/mcpserver/auth/test_auth_integration.py
@@ -1657,3 +1657,26 @@ async def test_authorize_invalid_scope(
         # State should be preserved
         assert "state" in query_params
         assert query_params["state"][0] == "test_state"
+
+
+@pytest.mark.anyio
+async def test_revoke_public_client_without_client_secret(
+    test_client: httpx2.AsyncClient, mock_oauth_provider: MockOAuthProvider
+):
+    response = await test_client.post(
+        "/register",
+        json={
+            "redirect_uris": ["https://client.example.com/callback"],
+            "token_endpoint_auth_method": "none",
+        },
+    )
+    assert response.status_code == 201
+    client_id = response.json()["client_id"]
+    mock_oauth_provider.tokens["public_token"] = AccessToken(
+        token="public_token", client_id=client_id, scopes=["read"], expires_at=int(time.time()) + 3600
+    )
+
+    response = await test_client.post("/revoke", data={"client_id": client_id, "token": "public_token"})
+
+    assert response.status_code == 200
+    assert await mock_oauth_provider.load_access_token("public_token") is None