diff --git a/.github/workflows/nix.yml b/.github/workflows/nix.yml
index 348e64db..829723f5 100644
--- a/.github/workflows/nix.yml
+++ b/.github/workflows/nix.yml
@@ -22,4 +22,7 @@ jobs:
       - name: Clone project
         uses: actions/checkout@v2
       - name: Build
-        run: nix build --print-build-logs
+        # "nix build" builds with full optimization and includes a profiling
+        # build, so just the build of xmonad-contrib itself takes 3 minutes.
+        # As a workaround, we invoke cabal manually here.
+        run: nix develop -c cabal v2-build -O0 -j
diff --git a/flake.nix b/flake.nix
index 1d7ec1bf..0e62a9ac 100644
--- a/flake.nix
+++ b/flake.nix
@@ -23,6 +23,7 @@
   rec {
     devShell = pkgs.haskellPackages.shellFor {
       packages = p: [ p.xmonad-contrib ];
+      nativeBuildInputs = [ pkgs.cabal-install ];
     };
     defaultPackage = pkgs.haskellPackages.xmonad-contrib;
   }) // { inherit overlay overlays; } ;