diff --git a/pkgs/development/haskell-modules/configuration-ghcjs.nix b/pkgs/development/haskell-modules/configuration-ghcjs.nix
index 5c14fe788f7a..ad482f1824b1 100644
--- a/pkgs/development/haskell-modules/configuration-ghcjs.nix
+++ b/pkgs/development/haskell-modules/configuration-ghcjs.nix
@@ -24,6 +24,7 @@ self: super:
 
   network = addBuildTools super.network (pkgs.lib.optional pkgs.stdenv.isDarwin pkgs.darwin.libiconv);
   zlib = addBuildTools super.zlib (pkgs.lib.optional pkgs.stdenv.isDarwin pkgs.darwin.libiconv);
+  unix-compat = addBuildTools super.unix-compat (pkgs.lib.optional pkgs.stdenv.isDarwin pkgs.darwin.libiconv);
 
   # LLVM is not supported on this GHC; use the latest one.
   inherit (pkgs) llvmPackages;