diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,1 +1,5 @@
+version 0.1.2: fix bug on hfixpoints
+
+version 0.1.1: fix dependency on regular
+
 version 0.1: initial release
diff --git a/regular-extras.cabal b/regular-extras.cabal
--- a/regular-extras.cabal
+++ b/regular-extras.cabal
@@ -1,5 +1,5 @@
 name:                   regular-extras
-version:                0.1.1
+version:                0.1.2
 synopsis:               Additional functions for regular: arbitrary,
                         coarbitrary, and binary get/put.
 description:
diff --git a/src/Generics/Regular/Functions/Fixpoints.hs b/src/Generics/Regular/Functions/Fixpoints.hs
--- a/src/Generics/Regular/Functions/Fixpoints.hs
+++ b/src/Generics/Regular/Functions/Fixpoints.hs
@@ -51,7 +51,7 @@
 instance (Fixpoints f, Fixpoints g) => Fixpoints (f :*: g) where
     hFixpoints (_ :: (f :*: g) a) = 
       let Leaf m = hFixpoints (undefined :: f a)
-          Leaf n = hFixpoints (undefined :: f b)
+          Leaf n = hFixpoints (undefined :: g a)
       in Leaf (m + n)
 
 instance Fixpoints I where