diff --git a/pyproject.toml b/pyproject.toml
index e3b351a0..80771097 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,7 @@ classifiers = [
     "Operating System :: OS Independent",
 ]
 dependencies = [
-    "numpy>=1.20",
+    "numpy>=1.20, <2.0",
     "scipy",
     "xarray",
     "autograd",