diff --git a/pyproject.toml b/pyproject.toml
index da19c11bef..d14db5d0bd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,7 +58,7 @@ dependencies = [
   "websockets>=15.0.1,<16",
 ]
 optional-dependencies.a2a = [
-  "a2a-sdk>=0.3.4,<2",
+  "a2a-sdk[http-server]>=0.3.4,<2",
 ]
 optional-dependencies.agent-identity = [
   "google-cloud-agentidentitycredentials>=0.1,<0.2",