diff --git a/ghc/lib/ghc/PrelBase.lhs b/ghc/lib/ghc/PrelBase.lhs
index 97ac8c35ee92fc8225a75cc9e18dfb42377f6c3e..aa8ee6f8e83305b0cf48966239c17bc6dc39cc9d 100644
--- a/ghc/lib/ghc/PrelBase.lhs
+++ b/ghc/lib/ghc/PrelBase.lhs
@@ -632,6 +632,8 @@ data Integer	= J# Int# Int# ByteArray#
 %*********************************************************
 
 \begin{code}
+instance Eval (a -> b) 
+
 instance  Show (a -> b)  where
     showsPrec p f  =  showString "<<function>>"
     showList ls	   = showList__ (showsPrec 0) ls