diff --git a/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix b/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix
index 8972aa60ad2..b6a817b9bf5 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-7.8.x.nix
@@ -37,8 +37,8 @@ self: super: {
   # mtl 2.2.x needs the latest transformers.
   mtl_2_2_1 = super.mtl_2_2_1.override { transformers = self.transformers_0_4_2_0; };
 
-  # https://github.com/RyanGlScott/mtl-compat/issues/1
-  mtl-compat = markBrokenVersion "0.1.1" super.mtl-compat;
+  # Configure build for mtl 2.1.x.
+  mtl-compat = addBuildDepend (enableCabalFlag super.mtl-compat "two-point-one") self.transformers-compat;
 
   # Idris requires mtl 2.2.x.
   idris = overrideCabal (super.idris.overrideScope (self: super: {