diff --git a/setup.py b/setup.py
index edf3fca906..f761210021 100644
--- a/setup.py
+++ b/setup.py
@@ -169,6 +169,7 @@
     "pydantic >= 2.11.1, < 3",
     "typing_extensions",
     "google-cloud-iam",
+    "aiohttp",  # for ADK users to use aiohttp rather than httpx client
 ]
 
 evaluation_extra_require = [