diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 5f60a87..32b8012 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,7 +2,7 @@ name: Build
 
 on:
   push:
-    branches: [main]
+    branches: [main, numpy1py39]
   pull_request:
     branches: [main]
 
diff --git a/pyproject.toml b/pyproject.toml
index 896de5d..f99f402 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,7 +28,8 @@ classifiers = [
 ]
 dependencies = [
     "torch",
-    "numpy",
+    "numpy>=2.1.1; python_version>='3.10'",
+    "numpy<2.0.0; python_version<'3.10'",
 ]
 
 [project.urls]