diff --git a/Database/PostgreSQL/ORM.hs b/Database/PostgreSQL/ORM.hs
--- a/Database/PostgreSQL/ORM.hs
+++ b/Database/PostgreSQL/ORM.hs
@@ -19,7 +19,7 @@
   -- ** Chaining associations
   , nestAssoc, chainAssoc
   -- ** Validations
-  , ValidationError(..), validate, validateNotEmpty
+  , ValidationError(..), validate, validateNotEmpty, validationError
   ) where
 
 import Database.PostgreSQL.ORM.Model
diff --git a/Database/PostgreSQL/ORM/Validations.hs b/Database/PostgreSQL/ORM/Validations.hs
--- a/Database/PostgreSQL/ORM/Validations.hs
+++ b/Database/PostgreSQL/ORM/Validations.hs
@@ -28,14 +28,18 @@
 
 type ValidationFunc a = a -> ValidationError
 
+validationError :: T.Text -> T.Text -> ValidationError
+validationError columnName description =
+    ValidationError $ H.singleton columnName [description]
+
 validate :: (a -> Bool)
          -> T.Text -- ^ Column name
          -> T.Text -- ^ Error description
          -> ValidationFunc a
 validate validator columnName desc = \a ->
-  if validator a then
-    ValidationError H.empty
-    else ValidationError $ H.singleton columnName [desc]
+  if validator a
+    then mempty
+    else validationError columnName desc
 
 validateNotEmpty :: (a -> T.Text)
                  -> T.Text
diff --git a/postgresql-orm.cabal b/postgresql-orm.cabal
--- a/postgresql-orm.cabal
+++ b/postgresql-orm.cabal
@@ -1,5 +1,5 @@
 name: postgresql-orm
-version: 0.4.0
+version: 0.4.1
 cabal-version: >= 1.14
 build-type: Simple
 license: GPL