diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9906cce..90220d9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -22,7 +22,6 @@ jobs:
         run: |
           set -Eeu
           matrix="$(nix eval --accept-flake-config --json '.#githubActions.matrix')"
-          echo $matrix
           echo "matrix=$matrix" >> "$GITHUB_OUTPUT"
 
   build:
@@ -32,7 +31,7 @@ jobs:
       fail-fast: false
       matrix: ${{ fromJSON(needs.define-matrix.outputs.matrix) }}
     concurrency:
-      group: ${{ github.workflow }}.${{ github.event.pull_request.number || github.ref }}.${{ matrix.attr }}
+      group: ${{ github.workflow }}.${{ github.event.pull_request.number || github.ref }}.${{ matrix.host }}
       cancel-in-progress: true
 
     steps:
@@ -52,5 +51,5 @@ jobs:
           name: joinemm
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
       
-      - name: Build ${{ matrix.attr }}
-        run: nixos-rebuild build -v --accept-flake-config --flake ".#${{ matrix.attr }}"
+      - name: Build ${{ matrix.host }}
+        run: nixos-rebuild build -v --accept-flake-config --flake ".#${{ matrix.host }}"
diff --git a/githubMatrix.nix b/githubMatrix.nix
index a985daa..5554ae6 100644
--- a/githubMatrix.nix
+++ b/githubMatrix.nix
@@ -3,8 +3,10 @@
   lib,
   ...
 }: {
-  flake.githubActions.matrix =
-    # can't build aarch64 on github
-    lib.subtractLists ["archimedes"]
-    (builtins.attrNames self.nixosConfigurations);
+  flake.githubActions.matrix = {
+    host =
+      # can't build aarch64 on github
+      lib.subtractLists ["archimedes"]
+      (builtins.attrNames self.nixosConfigurations);
+  };
 }