diff --git a/setup.py b/setup.py
index 2e50a5a57..53af91c0c 100644
--- a/setup.py
+++ b/setup.py
@@ -209,7 +209,7 @@ def read(fname):
         'urllib3<2',
         'appdirs',
         'future',
-        'numpy',
+        'numpy<2',
         'Pillow>=10.0.0',
         'PyYAML',
         'zeroc-ice>=3.6.5,<3.7',