diff --git a/postgrest.cabal b/postgrest.cabal
index d2ec20d6a..e04d4a65e 100644
--- a/postgrest.cabal
+++ b/postgrest.cabal
@@ -98,7 +98,7 @@ library
   Exposed-Modules:     PostgREST.App
                      , PostgREST.Types
                      , PostgREST.Parsers
-                     , PostgREST.Functions
+                     , PostgREST.QueryBuilder
                      , PostgREST.Auth
                      , PostgREST.Config
                      , PostgREST.Error
@@ -121,7 +121,7 @@ Test-Suite spec
   Other-Modules:       PostgREST.App
                      , PostgREST.Types
                      , PostgREST.Parsers
-                     , PostgREST.Functions
+                     , PostgREST.QueryBuilder
                      , PostgREST.Auth
                      , PostgREST.Config
                      , PostgREST.Error
diff --git a/src/PostgREST/App.hs b/src/PostgREST/App.hs
index afee8f239..487581e17 100644
--- a/src/PostgREST/App.hs
+++ b/src/PostgREST/App.hs
@@ -52,7 +52,7 @@ import PostgREST.PgQuery
 import PostgREST.RangeQuery
 import PostgREST.PgStructure
 import PostgREST.Parsers
-import PostgREST.Functions
+import PostgREST.QueryBuilder
 
 import Prelude
 
@@ -78,7 +78,7 @@ app dbstructure conf reqBody dbrole req =
       else
         -- return $ responseLBS status416 [] $ cs $ show queries
         case queries of
-          Left e -> return $ responseLBS status200 [("Content-Type", "text/plain")] $ cs e
+          Left e -> return $ responseLBS status400 [("Content-Type", "text/plain")] $ cs e
           Right (qs, cqs) -> do
             let qt = qualify table
                 count = if hasPrefer "count=none"
diff --git a/src/PostgREST/Auth.hs b/src/PostgREST/Auth.hs
index 9cd8cf779..2e60448c5 100644
--- a/src/PostgREST/Auth.hs
+++ b/src/PostgREST/Auth.hs
@@ -1,6 +1,3 @@
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE QuasiQuotes         #-}
-{-# LANGUAGE ScopedTypeVariables #-}
 module PostgREST.Auth where
 
 import           Control.Applicative
diff --git a/src/PostgREST/Main.hs b/src/PostgREST/Main.hs
index f4d5c4787..b4ba1bc1b 100644
--- a/src/PostgREST/Main.hs
+++ b/src/PostgREST/Main.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE QuasiQuotes         #-}
-{-# LANGUAGE ScopedTypeVariables #-}
 module Main where
 
 
diff --git a/src/PostgREST/Parsers.hs b/src/PostgREST/Parsers.hs
index 794b94e7a..1e74cdd46 100644
--- a/src/PostgREST/Parsers.hs
+++ b/src/PostgREST/Parsers.hs
@@ -1,7 +1,6 @@
---{-# LANGUAGE QuasiQuotes, ScopedTypeVariables, OverloadedStrings, FlexibleContexts #-}
 module PostgREST.Parsers
--- ( parseGetRequest
--- )
+( parseGetRequest
+)
 where
 
 import           Control.Applicative hiding ((<$>))
diff --git a/src/PostgREST/PgStructure.hs b/src/PostgREST/PgStructure.hs
index 6ea26f260..cbe784472 100644
--- a/src/PostgREST/PgStructure.hs
+++ b/src/PostgREST/PgStructure.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
-{-# LANGUAGE OverloadedStrings     #-}
 {-# LANGUAGE QuasiQuotes           #-}
-{-# LANGUAGE ScopedTypeVariables   #-}
 {-# LANGUAGE TypeSynonymInstances  #-}
 module PostgREST.PgStructure where
 
@@ -10,9 +8,7 @@ import           Data.List             (find)
 import           Data.Text             (Text, split)
 import           PostgREST.PgQuery     ()
 import           PostgREST.Types
---import Data.Aeson
 import           Data.Functor.Identity
---import Data.String.Conversions (cs)
 import           Control.Applicative
 import           Data.Maybe            (fromMaybe, isJust, mapMaybe)
 import Data.Monoid
diff --git a/src/PostgREST/Functions.hs b/src/PostgREST/QueryBuilder.hs
similarity index 99%
rename from src/PostgREST/Functions.hs
rename to src/PostgREST/QueryBuilder.hs
index 2338d7ad9..0f7d5fd50 100644
--- a/src/PostgREST/Functions.hs
+++ b/src/PostgREST/QueryBuilder.hs
@@ -1,5 +1,4 @@
-{-# LANGUAGE OverloadedStrings #-}
-module PostgREST.Functions
+module PostgREST.QueryBuilder
 where