diff --git a/python/requirements-dev.txt b/python/requirements-dev.txt
index e1404f5da..7582d753c 100644
--- a/python/requirements-dev.txt
+++ b/python/requirements-dev.txt
@@ -1,6 +1,6 @@
 
 bandit
-numpy
+numpy<2.0
 setuptools
 setuptools_scm
 pytest
diff --git a/python/setup.py b/python/setup.py
index bfe63589f..4bbc82283 100755
--- a/python/setup.py
+++ b/python/setup.py
@@ -36,7 +36,7 @@ def get_long_description():
     packages = ['dlisio', 'dlisio.dlis', 'dlisio.lis', 'dlisio.common', 'dlisio.dlis.utils'],
     license = 'LGPL-3.0',
     platforms = 'any',
-    install_requires = ['numpy'],
+    install_requires = ['numpy < 2.0'],
     setup_requires = ['setuptools >= 28',
                       'pybind11 >= 2.3',
                       'setuptools_scm',