diff --git a/default.nix b/default.nix
index ccb5a6e02..a13103e3b 100644
--- a/default.nix
+++ b/default.nix
@@ -43,6 +43,7 @@ let iosSupport = system == "x86_64-darwin";
           inherit (self) lib;
           haskellLib = self.haskell.lib;
           inherit
+            system
             useFastWeak useReflexOptimizer enableLibraryProfiling enableTraceReflexEvents
             useTextJSString enableExposeAllUnfoldings
             haskellOverlays;
diff --git a/haskell-overlays/default.nix b/haskell-overlays/default.nix
index ca4a29d1f..ffff922ea 100644
--- a/haskell-overlays/default.nix
+++ b/haskell-overlays/default.nix
@@ -1,4 +1,5 @@
-{ lib
+{ system
+, lib
 , haskellLib
 , nixpkgs
 , useFastWeak, useReflexOptimizer, enableLibraryProfiling, enableTraceReflexEvents
@@ -112,7 +113,7 @@ rec {
 
   # Just for GHCJS
   ghcjs = import ./ghcjs.nix {
-    inherit lib haskellLib nixpkgs fetchgit fetchFromGitHub useReflexOptimizer;
+    inherit system lib haskellLib nixpkgs fetchgit fetchFromGitHub useReflexOptimizer;
   };
   ghcjs-fast-weak = import ./ghcjs-fast-weak {
    inherit lib;
diff --git a/haskell-overlays/ghcjs.nix b/haskell-overlays/ghcjs.nix
index ffe2c9303..3bdec99a9 100644
--- a/haskell-overlays/ghcjs.nix
+++ b/haskell-overlays/ghcjs.nix
@@ -1,8 +1,20 @@
-{ lib, haskellLib, nixpkgs, fetchgit, fetchFromGitHub, useReflexOptimizer }:
+{ system, lib, haskellLib, nixpkgs, fetchgit, fetchFromGitHub, useReflexOptimizer }:
 
 with haskellLib;
 
-self: super: {
+self: super:
+
+# Workaround for https://github.com/ghcjs/ghcjs/issues/674
+# 'os (osx)' will always evaluate to 'false'
+let dontHardcodeLinux = package: cabalFile:
+  if ! self.ghc.isGhcjs then package
+  else nixpkgs.haskell.lib.overrideCabal package (drv: {
+    postPatch = (drv.postPatch or "") + nixpkgs.lib.optionalString (system == "x86_64-darwin") ''
+      substituteInPlace ${cabalFile}.cabal --replace 'if os(linux)' 'if os(linux) && !impl(ghcjs)'
+      substituteInPlace ${cabalFile}.cabal --replace 'if os(osx)' 'if os(linux) && impl(ghcjs)'
+    '';
+  });
+in {
   _dep = super._dep or {} // {
     ghcjsBaseSrc = fetchgit {
       url = "https://github.com/ghcjs/ghcjs-base.git";
@@ -82,4 +94,6 @@ self: super: {
       sha256 = "1sy51nz096sv91nxqk6yk7b92b5a40axv9183xakvki2nc09yhqg";
     };
   }));
+
+  foundation = dontHardcodeLinux super.foundation "foundation";
 }