diff --git a/tests/test_mcp_server.py b/tests/test_mcp_server.py
index 1c05364..66b440b 100644
--- a/tests/test_mcp_server.py
+++ b/tests/test_mcp_server.py
@@ -4,6 +4,7 @@
 import os
 import subprocess
 import sys
+import threading
 import time
 
 import pytest
@@ -42,20 +43,56 @@ def test_stdio_initialize_and_tools_list(monkeypatch: pytest.MonkeyPatch) -> Non
     }
     initialized = {"jsonrpc": "2.0", "method": "notifications/initialized"}
     tools_list = {"jsonrpc": "2.0", "id": 2, "method": "tools/list", "params": {}}
-    input_text = "\n".join(json.dumps(m) for m in (init, initialized, tools_list)) + "\n"
 
-    proc = subprocess.run(
+    proc = subprocess.Popen(
         [sys.executable, "-m", "tiny_ntfy_mcp"],
-        input=input_text,
+        stdin=subprocess.PIPE,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
         text=True,
-        capture_output=True,
         env=os.environ.copy(),
-        timeout=5,
-        check=False,
     )
-    assert proc.returncode == 0, proc.stderr
+    responses: list[dict] = []
+    # Signalled by the reader once the tools/list response (id=2) is observed,
+    # so the main thread waits on a real event rather than racing a join timeout.
+    saw_tools_list = threading.Event()
+
+    # Stdin is intentionally kept open until the tools/list response arrives
+    # so that MCP's transport-close handler (mcp>=1.27.0) does not cancel the
+    # in-flight request before it can respond.
+    def _collect() -> None:
+        for raw in proc.stdout:
+            raw = raw.strip()
+            if not raw:
+                continue
+            msg = json.loads(raw)
+            responses.append(msg)
+            if msg.get("id") == 2:
+                saw_tools_list.set()
+                return
+
+    t = threading.Thread(target=_collect, daemon=True)
+    t.start()
+    try:
+        for msg in (init, initialized, tools_list):
+            proc.stdin.write(json.dumps(msg) + "\n")
+            proc.stdin.flush()
 
-    responses = [json.loads(line) for line in proc.stdout.splitlines()]
+        got_response = saw_tools_list.wait(timeout=5)
+    finally:
+        proc.stdin.close()
+        try:
+            proc.wait(timeout=5)
+        except subprocess.TimeoutExpired:
+            proc.kill()
+            proc.wait()
+        # Reader exits naturally once stdout closes; join to ensure no further
+        # writes to `responses` race the assertions below.
+        t.join(timeout=5)
+
+    stderr_output = proc.stderr.read()
+    assert got_response, f"timed out waiting for tools/list response. Got ids: {[r.get('id') for r in responses]}\nstderr: {stderr_output}"
+    assert proc.returncode == 0, stderr_output
     init_resp = next(r for r in responses if r.get("id") == 1)
     tools_resp = next(r for r in responses if r.get("id") == 2)