diff --git a/pyproject.toml b/pyproject.toml
index 3536a97..4708917 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -2,7 +2,7 @@
 requires = [
     "setuptools>=42",
     "wheel",
-    "numpy",
+    "numpy<2.0.0",
     "cython>=3.0a6"
 ]
 build-backend = "setuptools.build_meta"
@@ -14,4 +14,4 @@ testpaths = [
 ]
 
 [tool.black]
-line-length = 160
\ No newline at end of file
+line-length = 160