diff --git a/stack.yaml b/stack.yaml
index c241aa7..7bdeb7d 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1 +1,4 @@
+flags:
+  esqueleto:
+    postgresql: true
 resolver: nightly-2015-06-09
diff --git a/test/Test.hs b/test/Test.hs
index d1c5c9b..85acff8 100644
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -818,7 +818,7 @@ main = do
             , BlogPost "C" p2k ]
           ret <- select $
                  from $ \bp ->
-                 distinctOn [bp ^. BlogPostAuthorId] $ do
+                 distinctOn [bp ^. BlogPostAuthorId, bp ^. BlogPostTitle] $ do
                  orderBy [asc (bp ^. BlogPostAuthorId), desc (bp ^. BlogPostTitle)]
                  return bp
           liftIO $ ret `shouldBe` sortBy (comparing (blogPostAuthorId . entityVal)) [bpB, bpC]