diff --git a/cabal2nix.cabal b/cabal2nix.cabal
--- a/cabal2nix.cabal
+++ b/cabal2nix.cabal
@@ -1,5 +1,5 @@
 Name:                   cabal2nix
-Version:                1.38
+Version:                1.39
 Copyright:              Peter Simons, Andres Loeh
 License:                BSD3
 License-File:           LICENSE
@@ -10,7 +10,7 @@
 Synopsis:               Convert Cabal files into Nix build instructions
 Cabal-Version:          >= 1.8
 Build-Type:             Custom
-Tested-With:            GHC == 6.12.3, GHC == 7.0.4, GHC == 7.4.1
+Tested-With:            GHC == 6.12.3, GHC == 7.0.4, GHC == 7.4.1, GHC == 7.4.2
 Data-files:             README.md
 Description:
   The @cabal2nix@ utility converts Cabal files into Nix build instructions. The
@@ -25,14 +25,15 @@
   > Recognized URI schemes:
   >
   >   cabal://pkgname-pkgversion       download the specified package from Hackage
+  >   cabal://pkgname                  download latest version of the specified package from Hackage
   >   http://host/path                 fetch the Cabal file via HTTP
   >   file:///local/path               load the Cabal file from the local disk
   >   /local/path                      abbreviated version of file URI
   .
   The only required argument is the path to the cabal file. For example:
   .
-  > cabal2nix http://hackage.haskell.org/packages/archive/cabal2nix/1.38/cabal2nix.cabal
-  > cabal2nix cabal://cabal2nix-1.38
+  > cabal2nix http://hackage.haskell.org/packages/archive/cabal2nix/1.39/cabal2nix.cabal
+  > cabal2nix cabal://cabal2nix-1.39
   .
   If the @--sha256@ option has not been specified, cabal2nix calls
   @nix-prefetch-url@ to determine the hash automatically. This causes
@@ -46,7 +47,7 @@
   main-is:              Cabal2Nix.hs
   hs-source-dirs:       src
   Build-Depends:        base >= 3 && < 5, regex-posix, pretty, Cabal >= 1.8,
-                        filepath, directory, process, HTTP
+                        filepath, directory, process, HTTP, hackage-db
   Extensions:           PatternGuards, RecordWildCards, CPP
   Ghc-Options:          -Wall
   other-modules:        Cabal2Nix.CorePackages
diff --git a/src/Cabal2Nix/Hackage.hs b/src/Cabal2Nix/Hackage.hs
--- a/src/Cabal2Nix/Hackage.hs
+++ b/src/Cabal2Nix/Hackage.hs
@@ -2,7 +2,8 @@
 
 import Control.Monad ( unless )
 import Data.List ( isPrefixOf )
-import Data.Version ( showVersion )
+import Data.Maybe ( fromJust )
+import Data.Version ( showVersion, versionBranch )
 import Distribution.Package ( PackageIdentifier(..), PackageName(..) )
 import Distribution.Text
 import Network.HTTP ( getRequest, rspBody )
@@ -11,6 +12,8 @@
 import System.FilePath ( dropFileName, (</>), (<.>) )
 import System.Process ( readProcess )
 
+import qualified Distribution.Hackage.DB as DB
+
 data Ext = TarGz | Cabal deriving Eq
 
 showExt :: Ext -> String
@@ -48,7 +51,17 @@
 
 readCabalFile :: FilePath -> IO String
 readCabalFile path
-  | "cabal://" `isPrefixOf` path = let Just pid = simpleParse (drop 8 path) in readCabalFile (hackagePath pid Cabal)
+  | "cabal://" `isPrefixOf` path = do let pid p = fromJust $ simpleParse p
+                                          packageName = drop 8 path
+                                      case versionBranch $ pkgVersion $ pid packageName of
+                                        [] -> do
+                                          packageDescription <- DB.lookup packageName `fmap` DB.readHackage
+                                          case packageDescription of
+                                            Just d -> do
+                                              let version = showVersion $ last $ DB.keys d
+                                              readCabalFile $ hackagePath (pid $ packageName ++ "-" ++ version) Cabal
+                                            Nothing -> error "No such package"
+                                        _  -> readCabalFile $ hackagePath (pid packageName) Cabal
   | "http://"  `isPrefixOf` path = fetchUrl path
   | "file://"  `isPrefixOf` path = readCabalFile (drop 7 path)
   | otherwise                    = readFile path