diff --git a/cabal-debian.cabal b/cabal-debian.cabal
--- a/cabal-debian.cabal
+++ b/cabal-debian.cabal
@@ -1,5 +1,5 @@
 Name:           cabal-debian
-Version:        3.7
+Version:        3.8
 License:        BSD3
 License-File:   debian/copyright
 Author:         David Fox <dsf@seereason.com>
diff --git a/debian/changelog b/debian/changelog
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+haskell-cabal-debian (3.8) unstable; urgency=low
+
+  * Downcase the package name to build the datadir name in /usr/share,
+    this matches the paths in dist/autogen/Paths_packagename.
+
+ -- David Fox <dsf@seereason.com>  Mon, 14 Oct 2013 20:48:39 -0700
+
 haskell-cabal-debian (3.7) unstable; urgency=low
 
   * Change path to hackage tarball in watch file for hackage2.
diff --git a/src/Debian/Debianize/Atoms.hs b/src/Debian/Debianize/Atoms.hs
--- a/src/Debian/Debianize/Atoms.hs
+++ b/src/Debian/Debianize/Atoms.hs
@@ -78,6 +78,7 @@
     , intermediateFiles
     ) where
 
+import Data.Char (toLower)
 import Data.Generics (Data, Typeable)
 import Data.Lens.Lazy (Lens, lens, getL, modL)
 import Data.Map as Map (Map, fold, foldWithKey, insertWith, empty, insert)
@@ -374,8 +375,8 @@
 dataDir = lens g s
     where
       g atoms =
-          fmap (\ p -> let PackageName pkgname = pkgName. package $ p in
-                       "usr/share" </> pkgname) (getL packageDescription atoms)
+          fmap (\ p -> let PackageName pkgname = pkgName . package $ p in
+                       "usr/share" </> map toLower pkgname) (getL packageDescription atoms)
       s _ _ = error "setL dataDir"