diff --git a/.travis.yml b/.travis.yml
index 9321fd18f44..93dbb98d46d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -128,7 +128,7 @@ script:  # command output is not hidden
   # run hledger-lib/hledger functional tests, skipping the ones for addons
   - COLUMNS=80 stack exec -- shelltest --execdir -j16 tests -x /bin -x /addons
 
-  # - stack build --ghc-options=-Werror hledger-ui
+  - stack build --ghc-options=-Werror hledger-ui
   - stack build --ghc-options=-Werror hledger-web
   - stack build --ghc-options=-Werror hledger-api