diff --git a/conversion.cabal b/conversion.cabal
--- a/conversion.cabal
+++ b/conversion.cabal
@@ -1,7 +1,7 @@
 name:
   conversion
 version:
-  1.1.1
+  1.2
 synopsis:
   Universal converter between values of different types
 category:
diff --git a/library/Conversion.hs b/library/Conversion.hs
--- a/library/Conversion.hs
+++ b/library/Conversion.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE IncoherentInstances #-}
 module Conversion
 (
   Conversion(..), 
@@ -15,6 +16,13 @@
 -- to a value of type @b@.
 class Conversion a b where
   convert :: a -> b
+
+
+-- |
+-- Equivalent to 'id'.
+instance Conversion a a where
+  {-# INLINE convert #-}
+  convert = id
 
 
 -- |