3 files changed, 24 insertions, 22 deletions
diff --git a/testsuite/tests/deriving/should_fail/T8851.hs b/testsuite/tests/deriving/should_fail/T8851.hs
index 84f0ad4ac1..8b5c0e579d 100644
--- a/testsuite/tests/deriving/should_fail/T8851.hs
+++ b/testsuite/tests/deriving/should_fail/T8851.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving, ConstrainedClassMethods #-}
 
 module T8851 where
 
diff --git a/testsuite/tests/ghci/prog008/A.hs b/testsuite/tests/ghci/prog008/A.hs
index 6a85ca70ce..d724bd2c9c 100644
--- a/testsuite/tests/ghci/prog008/A.hs
+++ b/testsuite/tests/ghci/prog008/A.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE RankNTypes, MultiParamTypeClasses #-}
+{-# LANGUAGE AllowAmbiguousTypes #-} -- c3 is ambiguous!
 
 -- Tests a bug spotted by Claus in which the type
 -- of c3 was wrongly displayed in GHCi as
diff --git a/testsuite/tests/ghci/scripts/ghci025.hs b/testsuite/tests/ghci/scripts/ghci025.hs
index d5e2673113..b556509aa6 100644
--- a/testsuite/tests/ghci/scripts/ghci025.hs
+++ b/testsuite/tests/ghci/scripts/ghci025.hs
@@ -1,22 +1,23 @@
 {-# LANGUAGE RankNTypes, MultiParamTypeClasses #-}
-
-module T where
-
-import qualified Prelude as T(length,Monad,Integer)
-import qualified Data.ByteString as T(length)
-import Prelude(length,(+),(=<<),Monad(..),Maybe(..),Eq)
-import Data.Maybe
-import Control.Monad(Monad(..),MonadPlus(..))
-
-length :: T.Integer
-length = 0
-
-class N a
-class S a
-
-class C a b where
-  c1 :: N b => a -> b
-  c2 :: (N b,S b) => a -> b
-  c3 :: forall a. a -> b
-  c4 :: a1 -> b
-
+{-# LANGUAGE AllowAmbiguousTypes #-} -- c3 is ambiguous!
+
+module T where
+
+import qualified Prelude as T(length,Monad,Integer)
+import qualified Data.ByteString as T(length)
+import Prelude(length,(+),(=<<),Monad(..),Maybe(..),Eq)
+import Data.Maybe
+import Control.Monad(Monad(..),MonadPlus(..))
+
+length :: T.Integer
+length = 0
+
+class N a
+class S a
+
+class C a b where
+  c1 :: N b => a -> b
+  c2 :: (N b,S b) => a -> b
+  c3 :: forall a. a -> b
+  c4 :: a1 -> b
+