diff --git a/hsfm.cabal b/hsfm.cabal
index d479e1c..73413c0 100644
--- a/hsfm.cabal
+++ b/hsfm.cabal
@@ -147,3 +147,4 @@ Test-Suite spec
                       , hspec >= 1.3
                       , process
                       , unix
+                      , utf8-string