diff --git a/tests/control_plane/test_effect_runtime_integration.py b/tests/control_plane/test_effect_runtime_integration.py
index abcf49e3b5..5fb13f2c05 100644
--- a/tests/control_plane/test_effect_runtime_integration.py
+++ b/tests/control_plane/test_effect_runtime_integration.py
@@ -982,6 +982,12 @@ def write() -> dict[str, object]:
             assert json.loads(journal_path.read_text(encoding="utf-8")) == journal
     finally:
         lock_path.unlink(missing_ok=True)
+        cleanup_deadline = time.monotonic() + 3
+        while time.monotonic() < cleanup_deadline:
+            effect_runtime._reap_exited_runtime_child(info)
+            if not effect_runtime._pid_is_alive(original["pid"]):
+                break
+            time.sleep(0.025)
         if effect_runtime._pid_is_alive(original["pid"]):
             os.kill(int(original["pid"]), signal.SIGTERM)