diff --git a/setup.py b/setup.py
index 1f1895bf..a6313f3f 100644
--- a/setup.py
+++ b/setup.py
@@ -30,7 +30,7 @@
         "bioimageio.spec==0.4.9.post5",
         "bioimageio.core==0.5.11",
         "grpcio>=1.31",
-        "numpy",
+        "numpy<2",  # pytorch 2.2.2-py3.9_0 for macos is compiled with numpy 1.*
         "protobuf",
         "pyyaml",
         "xarray",
diff --git a/tests/test_server/test_grpc/test_fligh_control_servicer.py b/tests/test_server/test_grpc/test_fligh_control_servicer.py
index a2a5080b..52f32c41 100644
--- a/tests/test_server/test_grpc/test_fligh_control_servicer.py
+++ b/tests/test_server/test_grpc/test_fligh_control_servicer.py
@@ -23,7 +23,7 @@ def test_shutdown_event_is_not_set_while_pings_keep_coming():
     def _pinger():
         while not stop_pinger.is_set():
             servicer.Ping(None, None)
-            time.sleep(0.05)
+            time.sleep(0.01)
 
     pinger_thread = threading.Thread(target=_pinger, name="Pinger", daemon=True)
     pinger_thread.start()