diff --git a/src/google/adk/cli/cli_deploy.py b/src/google/adk/cli/cli_deploy.py
index 3301ca4431..16939c7a2d 100644
--- a/src/google/adk/cli/cli_deploy.py
+++ b/src/google/adk/cli/cli_deploy.py
@@ -63,7 +63,7 @@ def _ensure_agent_engine_dependency(requirements_txt_path: str) -> None:
   with open(requirements_txt_path, 'a', encoding='utf-8') as f:
     if requirements and not requirements.endswith('\n'):
       f.write('\n')
-    f.write('google-cloud-aiplatform[agent_engines]\n')
+    f.write(f'{_AGENT_ENGINE_REQUIREMENT}\n')
     f.write(f'google-adk=={__version__}\n')
 
 
@@ -1017,7 +1017,7 @@ def to_agent_engine(
     if not os.path.exists(requirements_txt_path):
       click.echo(f'Creating {requirements_txt_path}...')
       with open(requirements_txt_path, 'w', encoding='utf-8') as f:
-        f.write('google-cloud-aiplatform[agent_engines]\n')
+        f.write(f'{_AGENT_ENGINE_REQUIREMENT}\n')
         f.write(f'google-adk=={__version__}\n')
         click.echo(f'Using google-adk=={__version__} in requirements')
       click.echo(f'Created {requirements_txt_path}')
diff --git a/tests/unittests/cli/utils/test_cli_deploy.py b/tests/unittests/cli/utils/test_cli_deploy.py
index 45c296cc85..650da437d7 100644
--- a/tests/unittests/cli/utils/test_cli_deploy.py
+++ b/tests/unittests/cli/utils/test_cli_deploy.py
@@ -303,6 +303,13 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
   assert len(create_recorder.calls) == 1
   assert str(rmtree_recorder.get_last_call_args()[0]) == str(tmp_dir)
 
+  requirements_file = tmp_dir / "agents" / "agent" / "requirements.txt"
+  assert requirements_file.is_file()
+  assert (
+      "google-cloud-aiplatform[adk,agent_engines]"
+      in requirements_file.read_text()
+  )
+
 
 def test_to_agent_engine_raises_when_explicit_config_file_missing(
     monkeypatch: pytest.MonkeyPatch,
@@ -685,3 +692,25 @@ def test_cli_deploy_agent_engine_artifact_service_uri(tmp_path: Path):
     mock_to_agent_engine.assert_called_once()
     _, kwargs = mock_to_agent_engine.call_args
     assert kwargs["artifact_service_uri"] == "gs://my-bucket"
+
+
+def test_ensure_agent_engine_dependency(tmp_path: Path):
+  """Tests that _ensure_agent_engine_dependency appends correct extras."""
+  requirements_file = tmp_path / "requirements.txt"
+
+  # Case 1: raises FileNotFoundError when the file doesn't exist
+  with pytest.raises(FileNotFoundError):
+    cli_deploy._ensure_agent_engine_dependency(str(requirements_file))
+
+  # Case 2: appends both google-cloud-aiplatform with 'adk' and 'agent_engines' extras and versioned google-adk
+  requirements_file.write_text("")
+  cli_deploy._ensure_agent_engine_dependency(str(requirements_file))
+  content = requirements_file.read_text()
+  assert "google-cloud-aiplatform[adk,agent_engines]\n" in content
+  assert f"google-adk=={cli_deploy.__version__}\n" in content
+
+  # Case 3: does not append duplicate if google-cloud-aiplatform already exists
+  requirements_file.write_text("google-cloud-aiplatform[adk,agent_engines]\n")
+  cli_deploy._ensure_agent_engine_dependency(str(requirements_file))
+  content = requirements_file.read_text()
+  assert content == "google-cloud-aiplatform[adk,agent_engines]\n"