diff --git a/src/Handler/Course.hs b/src/Handler/Course.hs
index 4260a94b3..ccba2fdbb 100644
--- a/src/Handler/Course.hs
+++ b/src/Handler/Course.hs
@@ -788,7 +788,7 @@ makeCourseUserTable cid colChoices psValidator =
         -- , ("course-registration", error "TODO") -- TODO
         -- , ("course-user-note", error "TODO") -- TODO
         ]
-      dbtFilterUI  = \mPrev -> mconcat
+      dbtFilterUI mPrev = mconcat
         [ fltrUserNameLinkUI   mPrev
         , fltrUserMatriclenrUI mPrev
         ]