diff --git a/hlint.cabal b/hlint.cabal
--- a/hlint.cabal
+++ b/hlint.cabal
@@ -1,7 +1,7 @@
 cabal-version:      >= 1.6
 build-type:         Simple
 name:               hlint
-version:            1.8.50
+version:            1.8.51
 license:            BSD3
 license-file:       LICENSE
 category:           Development
@@ -41,7 +41,7 @@
         transformers >= 0.0,
         hscolour >= 1.17,
         cpphs >= 1.11,
-        haskell-src-exts >= 1.11,
+        haskell-src-exts >= 1.14 && < 1.15,
         uniplate >= 1.5
 
     hs-source-dirs:     src
diff --git a/src/CmdLine.hs b/src/CmdLine.hs
--- a/src/CmdLine.hs
+++ b/src/CmdLine.hs
@@ -133,7 +133,7 @@
             ,defines = [(a,drop 1 b) | Define x <- opt, let (a,b) = break (== '=') x]
             }
     let cpp | SimpleCpp `elem` opt = CppSimple -- must be first, so can disable CPP
-            | CPP `elem` languages = Cpphs cpphs
+            | EnableExtension CPP `elem` languages = Cpphs cpphs
             | otherwise = NoCpp
 
     encoding <- newEncoding $ last $ "" : [x | Encoding x <- opt]
diff --git a/src/Hint/Extensions.hs b/src/Hint/Extensions.hs
--- a/src/Hint/Extensions.hs
+++ b/src/Hint/Extensions.hs
@@ -4,6 +4,8 @@
 <TEST>
 {-# LANGUAGE Arrows #-} \
 f = id --
+{-# LANGUAGE TotallyUnknown #-} \
+f = id
 {-# LANGUAGE Foo, Generics, ParallelListComp, ImplicitParams #-} \
 f = [(a,c) | a <- b | c <- d] -- {-# LANGUAGE Foo, ParallelListComp #-}
 {-# LANGUAGE EmptyDataDecls #-} \
@@ -64,29 +66,33 @@
 
 extensionsHint :: ModuHint
 extensionsHint _ x = [rawIdea Error "Unused LANGUAGE pragma" (toSrcLoc sl)
-          (prettyPrint o) (if null new then "" else prettyPrint $ LanguagePragma sl $ map (toNamed . showExt) new)
+          (prettyPrint o) (if null new then "" else prettyPrint $ LanguagePragma sl $ map (toNamed . prettyExtension) new)
           (warnings old new)
     | not $ used TemplateHaskell x -- if TH is on, can use all other extensions programmatically
     , o@(LanguagePragma sl exts) <- modulePragmas x
-    , let old = map (classifyExtension . prettyPrint) exts
+    , let old = map (parseExtension . prettyPrint) exts
     , let new = minimalExtensions x old
     , sort new /= sort old]
-    where
-        showExt (UnknownExtension x) = x
-        showExt x = show x
 
 
 minimalExtensions :: Module_ -> [Extension] -> [Extension]
 minimalExtensions x es = nub $ concatMap f es
-    where f e = [e | used e x]
+    where f e = [e | usedExt e x]
 
 
 -- RecordWildCards implies DisambiguateRecordFields, but most people probably don't want it
-warnings old new | RecordWildCards `elem` old && RecordWildCards `notElem` new = [Note "you may need to add DisambiguateRecordFields"]
+warnings old new | wildcards `elem` old && wildcards `notElem` new = [Note "you may need to add DisambiguateRecordFields"]
+    where wildcards = EnableExtension RecordWildCards
 warnings _ _ = []
 
 
-used :: Extension -> Module_ -> Bool
+usedExt :: Extension -> Module_ -> Bool
+usedExt (UnknownExtension "DeriveGeneric") = hasDerive False ["Generic","Generic1"]
+usedExt (EnableExtension x) = used x
+usedExt _ = const True
+
+
+used :: KnownExtension -> Module_ -> Bool
 used RecursiveDo = hasS isMDo
 used ParallelListComp = hasS isParComp
 used FunctionalDependencies = hasT (un :: FunDep S)
@@ -118,10 +124,9 @@
 used QuasiQuotes = hasS isQuasiQuote
 used ViewPatterns = hasS isPViewPat
 used DeriveDataTypeable = hasDerive True ["Data","Typeable"]
-used (UnknownExtension "DeriveGeneric") = hasDerive False ["Generic","Generic1"]
-used (UnknownExtension "DeriveFunctor") = hasDerive False ["Functor"]
-used (UnknownExtension "DeriveFoldable") = hasDerive False ["Foldable"]
-used (UnknownExtension "DeriveTraversable") = hasDerive False ["Traversable"]
+used DeriveFunctor = hasDerive False ["Functor"]
+used DeriveFoldable = hasDerive False ["Foldable"]
+used DeriveTraversable = hasDerive False ["Traversable"]
 used GeneralizedNewtypeDeriving = not . null . filter (`notElem` special) . fst . derives
     where special = ["Read","Show","Data","Typeable"] -- these classes cannot use generalised deriving
 used Arrows = hasS f
@@ -136,8 +141,8 @@
           f _ = True
 
 -- for forwards compatibility, if things ever get added to the extension enumeration
-used (UnknownExtension _) = const True
-used x = used $ UnknownExtension $ show x
+used x = usedExt $ UnknownExtension $ show x
+
 
 
 hasDerive :: Bool -> [String] -> Module_ -> Bool
diff --git a/src/Proof.hs b/src/Proof.hs
--- a/src/Proof.hs
+++ b/src/Proof.hs
@@ -161,7 +161,7 @@
         exp (Var _ x) | Just x <- funs $ prettyPrint x = x
         exp (Con _ (Special _ (TupleCon _ _ i))) = "\\<langle>" ++ replicate (i-1) ',' ++ "\\<rangle>"
         exp (Con _ x) | Just x <- cons $ prettyPrint x = x
-        exp (Tuple _ xs) = "\\<langle>" ++ intercalate ", " (map exp xs) ++ "\\<rangle>"
+        exp (Tuple _ _ xs) = "\\<langle>" ++ intercalate ", " (map exp xs) ++ "\\<rangle>"
         exp (If _ a b c) = "If " ++ exp a ++ " then " ++ exp b ++ " else " ++ exp c
         exp (Lambda _ xs y) = "\\<Lambda> " ++ unwords (map pat xs) ++ ". " ++ exp y
         exp (InfixApp _ x op y) | Just op <- ops $ prettyPrint op =
@@ -173,7 +173,7 @@
         exp x@(RightSection l op e) = let v = fresh x in exp $ Paren l $ Lambda l [toNamed v] $ InfixApp l (toNamed v) op e -- S3.5
         exp x = prettyPrint x
 
-        pat (PTuple _ xs) = "\\<langle>" ++ intercalate ", " (map pat xs) ++ "\\<rangle>"
+        pat (PTuple _ _ xs) = "\\<langle>" ++ intercalate ", " (map pat xs) ++ "\\<rangle>"
         pat x = prettyPrint x
 
         fresh x = head $ ("z":["v" ++ show i | i <- [1..]]) \\ vars x
diff --git a/src/Util.hs b/src/Util.hs
--- a/src/Util.hs
+++ b/src/Util.hs
@@ -249,7 +249,7 @@
 -- LANGUAGE.HASKELL.EXTS.EXTENSION
 
 defaultExtensions :: [Extension]
-defaultExtensions = knownExtensions \\ badExtensions
+defaultExtensions = [e | e@EnableExtension{} <- knownExtensions] \\ map EnableExtension badExtensions
 
 badExtensions =
     [Arrows -- steals proc