diff --git a/pyproject.toml b/pyproject.toml
index b93ea61d..62514e61 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,6 +37,7 @@ version = "0.1.1"
 
 [project.optional-dependencies]
 dev = [
+    "cupy-cuda11x",
     "hypothesis",
     "pre-commit",
     "pytest",