diff --git a/pyproject.toml b/pyproject.toml
index b566795..4d5f08b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,6 +31,7 @@ classifiers = [
 dynamic = ["version"]
 dependencies = [
   "awkward>=2.6.7",
+  "numpy=2.0.0",
 ]
 
 [project.optional-dependencies]