diff --git a/stack-ghc-7.8.4.yaml b/stack-ghc-7.8.4.yaml
index 5ccd7069..b3b66e88 100644
--- a/stack-ghc-7.8.4.yaml
+++ b/stack-ghc-7.8.4.yaml
@@ -28,5 +28,6 @@ extra-deps:
 - should-not-typecheck-2.1.0
 - time-locale-compat-0.1.1.1
 - uri-bytestring-0.2.2.0
+- void-0.7.1
 - wai-app-static-3.1.5
 resolver: lts-2.22