diff --git a/pyproject.toml b/pyproject.toml
index f7ff79a7..ce498bf2 100755
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,7 @@ dependencies = [
     "forestci==0.6",
     "pathos==0.2.9",
     "pip>=10.0",
-    "numpy>=1.18.5",
+    "numpy>=1.18.5, <2",
     "scipy>=1.4.1",
     "matplotlib",
     "pandas>=0.24.1",
@@ -63,7 +63,7 @@ requires = [
     "setuptools>=18.0",
     "wheel",
     "Cython<=0.29.34",
-    "numpy>=1.18.5",
+    "numpy>=1.18.5, <2",
     "scikit-learn>=0.22.0",
 ]