diff --git a/.travis.yml b/.travis.yml
index 32f4ede..fd3a6b1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,7 @@ install:
   - which cabal
   - cabal install cabal-install --constraint "Cabal == $(cabal --version | grep 'Cabal library' | awk '{ print $3 }' | awk -vFS=. '{ print $1 "." $2 }' | tail -n1).*"
 #  - cabal install Cabal --constraint "Cabal == $(cabal --version | grep 'Cabal library' | awk '{ print $3 }' | tail -n1)"
+  - cabal install happy
   - happy --version
   - cabal install -j --only-dependencies --enable-tests