diff --git a/src/google/adk/cli/cli_tools_click.py b/src/google/adk/cli/cli_tools_click.py
index 12edb32993d..31d7cca26eb 100644
--- a/src/google/adk/cli/cli_tools_click.py
+++ b/src/google/adk/cli/cli_tools_click.py
@@ -20,6 +20,7 @@
 from datetime import datetime
 import functools
 import hashlib
+import importlib.util
 import json
 import logging
 import os
@@ -41,6 +42,7 @@
 from ..agents._streaming_mode import StreamingMode
 from ..features import FeatureName
 from ..features import override_feature_enabled
+from ..utils._dependency import missing_extra
 from ..utils._telemetry_config import read_telemetry_consent
 from ..utils._telemetry_config import write_telemetry_consent
 from ._telemetry._metrics_collector import MetricsCollector
@@ -1059,6 +1061,9 @@ def cli_test(ctx, folder: str, rebuild: bool):
     )
     sys.exit(1)
 
+  if importlib.util.find_spec("pytest") is None:
+    raise click.ClickException(str(missing_extra("pytest", "test")))
+
   click.echo(f"Running tests in {folder} using runner {test_runner_path}...")
 
   result = subprocess.run([
diff --git a/src/google/adk/cli/dev_server.py b/src/google/adk/cli/dev_server.py
index a3daaf7271e..14bcfa68124 100644
--- a/src/google/adk/cli/dev_server.py
+++ b/src/google/adk/cli/dev_server.py
@@ -31,6 +31,7 @@
 from __future__ import annotations
 
 import asyncio
+import importlib.util
 import json
 import logging
 import os
@@ -72,6 +73,7 @@
 from ..evaluation.eval_metrics import MetricInfo
 from ..evaluation.eval_result import EvalSetResult
 from ..evaluation.eval_set import EvalSet
+from ..utils._dependency import missing_extra
 from ..utils._telemetry_config import read_telemetry_consent
 from ..utils._telemetry_config import write_telemetry_consent
 from .api_server import ApiServer
@@ -826,6 +828,10 @@ async def run_pytest_subprocess():
         env["ADK_TEST_FOLDER"] = agent_dir
 
         try:
+          if importlib.util.find_spec("pytest") is None:
+            await queue.put(str(missing_extra("pytest", "test")) + "\n")
+            return
+
           process = await asyncio.create_subprocess_exec(
               *cmd_args,
               stdout=subprocess.PIPE,
diff --git a/tests/unittests/cli/test_adk_web_server_tests.py b/tests/unittests/cli/test_adk_web_server_tests.py
index 6dc13ed9e91..89f7f7dadf6 100644
--- a/tests/unittests/cli/test_adk_web_server_tests.py
+++ b/tests/unittests/cli/test_adk_web_server_tests.py
@@ -15,8 +15,10 @@
 from __future__ import annotations
 
 import asyncio
+import importlib.util
 import json
 import os
+from typing import Any
 from unittest.mock import AsyncMock
 from unittest.mock import MagicMock
 from unittest.mock import patch
@@ -155,3 +157,35 @@ def test_run_tests(test_client):
     content = response.content
     assert b"line1\n" in content
     assert b"line2\n" in content
+
+
+def test_run_tests_without_pytest_streams_the_test_extra(test_client):
+  """Without pytest the endpoint streams the extra and spawns no child."""
+  real_find_spec = importlib.util.find_spec
+
+  def _fake_find_spec(name: str, *args: Any, **kwargs: Any):
+    if name == "pytest":
+      return None
+    return real_find_spec(name, *args, **kwargs)
+
+  # The fake child exits immediately, so a regression that spawns it fails the
+  # assertions below instead of blocking the stream.
+  mock_process = MagicMock()
+  mock_process.stdout.readline = AsyncMock(return_value=b"")
+  mock_process.wait = AsyncMock(return_value=0)
+
+  with (
+      patch.object(importlib.util, "find_spec", _fake_find_spec),
+      patch(
+          "google.adk.cli.dev_server.asyncio.create_subprocess_exec",
+          new_callable=AsyncMock,
+      ) as mock_create_subprocess,
+  ):
+    mock_create_subprocess.return_value = mock_process
+
+    response = test_client.post("/dev/apps/test_app/tests/run", json={})
+
+    assert response.status_code == 200
+    assert b"pip install google-adk[test]" in response.content
+    assert b"No module named pytest" not in response.content
+    mock_create_subprocess.assert_not_called()
diff --git a/tests/unittests/cli/utils/test_cli_tools_click.py b/tests/unittests/cli/utils/test_cli_tools_click.py
index 354962ce1a8..306974217d0 100644
--- a/tests/unittests/cli/utils/test_cli_tools_click.py
+++ b/tests/unittests/cli/utils/test_cli_tools_click.py
@@ -18,6 +18,7 @@
 
 import builtins
 import hashlib
+import importlib.util
 import json
 import logging
 import os
@@ -2638,6 +2639,27 @@ def test_cli_test_exits_with_the_pytest_return_code(
   assert result.exit_code == 3
 
 
+def test_cli_test_names_the_test_extra_when_pytest_is_missing(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, fake_pytest_run
+) -> None:
+  """Without pytest the command names the extra instead of spawning a child."""
+  real_find_spec = importlib.util.find_spec
+
+  def _fake_find_spec(name: str, *args: Any, **kwargs: Any):
+    if name == "pytest":
+      return None
+    return real_find_spec(name, *args, **kwargs)
+
+  monkeypatch.setattr(importlib.util, "find_spec", _fake_find_spec)
+
+  result = CliRunner().invoke(cli_tools_click.main, ["test", str(tmp_path)])
+
+  assert result.exit_code == 1
+  assert "pip install google-adk[test]" in result.output
+  assert "No module named pytest" not in result.output
+  assert fake_pytest_run.runs == []
+
+
 def test_cli_test_rebuild_skips_the_pytest_subprocess(
     tmp_path: Path, monkeypatch: pytest.MonkeyPatch, fake_pytest_run
 ) -> None: