diff --git a/src/Database/Esqueleto/Utils.hs b/src/Database/Esqueleto/Utils.hs
index b2e077453..bac61ff27 100644
--- a/src/Database/Esqueleto/Utils.hs
+++ b/src/Database/Esqueleto/Utils.hs
@@ -80,7 +80,7 @@ import qualified Data.Text.Lazy.Builder as Text.Builder
 import Data.Monoid (Last(..))
 
 import Utils (commaSeparatedText)
-import Utils.Set (concatMapSet)
+-- import Utils.Set (concatMapSet)
 
 
 {-# ANN any ("HLint: ignore Use any" :: String) #-}
@@ -335,7 +335,7 @@ mkContainsFilterWith cast lenslike row criterias
   | otherwise = any (hasInfix $ lenslike row) (E.val . cast <$> Set.toList criterias)
 
 -- | like `mkContainsFilterWith` but allows conversion to produce multiple needles
-mkContainsFilterWithSet :: (E.SqlString b, Ord b)
+mkContainsFilterWithSet :: (E.SqlString b, Ord b, Ord a)
                      => (a -> Set.Set b)
                      -> (t -> E.SqlExpr (E.Value b))  -- ^ getter from query to searched element
                      -> t                             -- ^ query row
@@ -343,7 +343,7 @@ mkContainsFilterWithSet :: (E.SqlString b, Ord b)
                      -> E.SqlExpr (E.Value Bool)
 mkContainsFilterWithSet cast lenslike row criterias
   | Set.null criterias = true
-  | otherwise = any (hasInfix $ lenslike row) (E.val <$> Set.toList (concatMapSet cast criterias))
+  | otherwise = any (hasInfix $ lenslike row) (E.val <$> Set.toList (foldMap cast criterias))
 
 -- | like `mkContainsFilterWithSet` but fixed to comma separated Texts
 mkContainsFilterWithComma :: (E.SqlString b, Ord b)
@@ -352,7 +352,7 @@ mkContainsFilterWithComma :: (E.SqlString b, Ord b)
                      -> t                             -- ^ query row
                      -> Set.Set Text                  -- ^ needle collection
                      -> E.SqlExpr (E.Value Bool)
-mkContainsFilterWithComma cast lenslike row (concatMapSet commaSeparatedText -> criterias)
+mkContainsFilterWithComma cast lenslike row (foldMap commaSeparatedText -> criterias)
   | Set.null criterias = true
   | otherwise = any (hasInfix $ lenslike row) (E.val . cast <$> Set.toList criterias)
 
@@ -363,7 +363,7 @@ mkContainsFilterWithCommaPlus :: (E.SqlString b, Ord b)
                      -> t                             -- ^ query row
                      -> Set.Set Text                  -- ^ needle collection
                      -> E.SqlExpr (E.Value Bool)
-mkContainsFilterWithCommaPlus cast lenslike row (concatMapSet commaSeparatedText -> criterias)
+mkContainsFilterWithCommaPlus cast lenslike row (foldMap commaSeparatedText -> criterias)
   | Set.null criterias    = true
   | Set.null compulsories = cond_optional
   | Set.null alternatives = cond_compulsory
diff --git a/src/Utils/Set.hs b/src/Utils/Set.hs
index 7fb14cdfa..7ef167280 100644
--- a/src/Utils/Set.hs
+++ b/src/Utils/Set.hs
@@ -58,7 +58,7 @@ setMapMaybe f = Set.fromList . mapMaybe f . Set.toList
 
 concatMapSet :: Ord b => (a -> Set b) -> Set a -> Set b
 concatMapSet f = Set.foldl ((. f) . (<>)) mempty
--- concatMapSet f = foldMap f --- requires Ord a as well
+-- concatMapSet f = foldMap f --- requires Ord a as well, which we ought to have anyway
 
 -- | Symmetric difference of two sets.
 setSymmDiff :: Ord a => Set a -> Set a -> Set a