diff --git a/riff.cabal b/riff.cabal
--- a/riff.cabal
+++ b/riff.cabal
@@ -10,7 +10,7 @@
 -- PVP summary:      +-+------- breaking API changes
 --                   | | +----- non-breaking API additions
 --                   | | | +--- code changes with no API change
-version:             0.3.0.0
+version:             0.3.0.1
 
 -- A short (one-line) description of the package.
 synopsis:            RIFF parser for Haskell
@@ -75,8 +75,8 @@
   build-depends:       base >=4.5 && <5.0
                        , binary >=0.7 && <0.8
                        , bytestring >=0.9 && <1.0
-                       , either >=4.1 && <4.2
-                       , transformers >=0.3.0 && <0.3.1
+                       , either == 4.3.*
+                       , transformers == 0.4.*
   
   -- Directories containing source files.
   -- hs-source-dirs: