diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+version 0.2.4:
+  - Export Assoc(..) from Generics.Regular.Functions.Crush (thanks to Martijn
+    van Steenbergen).
+
 version 0.2.3:
   - Replaced the flag on the cabal package by an explicit test on the ghc
     version. This makes it easier to build on ghc-6.12.
diff --git a/regular.cabal b/regular.cabal
--- a/regular.cabal
+++ b/regular.cabal
@@ -1,5 +1,5 @@
 name:                   regular
-version:                0.2.3
+version:                0.2.4
 synopsis:               Generic programming library for regular datatypes.
 description:
 
diff --git a/src/Generics/Regular/Functions/Crush.hs b/src/Generics/Regular/Functions/Crush.hs
--- a/src/Generics/Regular/Functions/Crush.hs
+++ b/src/Generics/Regular/Functions/Crush.hs
@@ -16,7 +16,7 @@
 module Generics.Regular.Functions.Crush (
 
   -- * Crush functions
-  Crush (..),
+  Crush (..), Assoc(..),
   flattenl, flattenr, crushr, crushl
 
 ) where
diff --git a/src/Generics/Regular/Functions/Zip.hs b/src/Generics/Regular/Functions/Zip.hs
--- a/src/Generics/Regular/Functions/Zip.hs
+++ b/src/Generics/Regular/Functions/Zip.hs
@@ -49,7 +49,7 @@
 instance (Zip f, Zip g) => Zip (f :+: g) where
   fzipM f (L x) (L y) = liftM L (fzipM f x y)
   fzipM f (R x) (R y) = liftM R (fzipM f x y)
-  fzipM _ _       _       = fail "fzipM: structure mismatch"
+  fzipM _ _       _   = fail "fzipM: structure mismatch"
 
 instance (Zip f, Zip g) => Zip (f :*: g) where
   fzipM f (x1 :*: y1) (x2 :*: y2) =