diff --git a/type-eq.cabal b/type-eq.cabal
--- a/type-eq.cabal
+++ b/type-eq.cabal
@@ -1,6 +1,6 @@
 name:          type-eq
 category:      Type System
-version:       0.4
+version:       0.4.1
 author:        Gábor Lehel
 maintainer:    Gábor Lehel <glaebhoerl@gmail.com>
 homepage:      http://github.com/glaebhoerl/type-eq
@@ -67,6 +67,9 @@
         Type.Eq.Unsafe
         Type.Eq.Higher
         Type.Eq.Higher.Unsafe
+
+    ghc-options: -pgmPcpphs -optP--cpp
+    build-tools: cpphs
 
 -- DeriveDataTypeable and PolyKinds sadly don't mix
 --    if impl(ghc)