diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 585f327d3..48f173c83 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -78,19 +78,11 @@ jobs:
         uses: ./.github/actions/setup-nix
         with:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-      - name: Install gnu sed
-        run: brew install gnu-sed
+      - name: Install nix-build-uncached
+        run: nix-env -f default.nix -iA nix-build-uncached
 
-      - name: Build everything
-        run: |
-          # The --dry-run will give us a list of derivations to download from cachix and
-          # derivations to build. We only take those that would have to be built and then build
-          # those explicitly. This has the advantage that pure verification will not include
-          # a download anymore, making it much faster. If something needs to be built, only
-          # the dependencies required to do so will be downloaded, but not everything.
-          nix-build --dry-run 2>&1 \
-            | gsed -e '1,/derivations will be built:$/d' -e '/paths will be fetched/Q' \
-            | xargs nix-build
+      - name: Build everything (default.nix)
+        run: nix-build-uncached
 
 
   stack:
diff --git a/default.nix b/default.nix
index f19279232..859c3ebb4 100644
--- a/default.nix
+++ b/default.nix
@@ -107,6 +107,9 @@ rec {
       inherit (pkgs.haskell.packages."${compiler}") ghcWithPackages;
     };
 
+  # Used by CI on MacOS
+  inherit (pkgs) nix-build-uncached;
+
   ### Tools
 
   cabalTools =