diff --git a/unliftio/package.yaml b/unliftio/package.yaml
index ec8fbb8..22bb04f 100644
--- a/unliftio/package.yaml
+++ b/unliftio/package.yaml
@@ -68,6 +68,7 @@ tests:
   unliftio-spec:
     source-dirs:
     - test
+    build-tools: hspec-discover
     main: Spec.hs
     dependencies:
     - hspec