diff --git a/pkgs/development/libraries/haskell/snap/snap.nix b/pkgs/development/libraries/haskell/snap/snap.nix
index 505c9bcb0cc3..4121a657357f 100644
--- a/pkgs/development/libraries/haskell/snap/snap.nix
+++ b/pkgs/development/libraries/haskell/snap/snap.nix
@@ -19,6 +19,9 @@ cabal.mkDerivation (self: {
     snapServer stm syb text time transformers unorderedContainers
     utf8String vector vectorAlgorithms xmlhtml
   ];
+  patchPhase = ''
+    sed -i snap.cabal -e 's|clientsession.*,|clientsession,|'
+  '';
   meta = {
     homepage = "http://snapframework.com/";
     description = "Snap: A Haskell Web Framework: project starter executable and glue code library";