diff --git a/requirements.txt b/requirements.txt
index fdebcba..f964518 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,7 @@
 six==1.14.0
 
 # Test and documentation
+numpy<2; python_version>='3.8'
 pandas==1.5.3; python_version>='3.8'
 setuptools==70.0.0; python_version>='3.8'
 wheel
\ No newline at end of file