diff --git a/src/Control/Monad/Logger/Sticky.hs b/src/Control/Monad/Logger/Sticky.hs
index 374ea26aeb..10eec7165f 100644
--- a/src/Control/Monad/Logger/Sticky.hs
+++ b/src/Control/Monad/Logger/Sticky.hs
@@ -25,6 +25,8 @@ import           Language.Haskell.TH
 import           System.IO
 import           System.Log.FastLogger
 
+import           Prelude -- avoid AMP warnings
+
 data State = State
     { stateCurrentLine :: !(Maybe ByteString)
     , stateMaxColumns :: !Int
diff --git a/src/test/Stack/BuildPlanSpec.hs b/src/test/Stack/BuildPlanSpec.hs
index 6cc7836479..b8c5fc8e16 100644
--- a/src/test/Stack/BuildPlanSpec.hs
+++ b/src/test/Stack/BuildPlanSpec.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE TemplateHaskell #-}
diff --git a/src/test/Stack/ConfigSpec.hs b/src/test/Stack/ConfigSpec.hs
index 0d6ed922b0..af7076161f 100644
--- a/src/test/Stack/ConfigSpec.hs
+++ b/src/test/Stack/ConfigSpec.hs
@@ -1,5 +1,6 @@
-{-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE RecordWildCards  #-}
+{-# LANGUAGE TemplateHaskell  #-}
 module Stack.ConfigSpec where
 
 import Control.Applicative