diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2d65c9873..aa19b8fb3 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -25,9 +25,10 @@ jobs:
           name: trilitech-jstz
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
 
-      - run: nix shell --run "make fmt"
+      - run: nix develop --command bash -c "make fmt"
 
   build:
+    name: Build `jstz_kernel`
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
@@ -45,9 +46,6 @@ jobs:
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
 
       - run: nix build
-      - run: nix shell --run "echo OK"
-
-      - run: cachix push trilitech-jstz result --watch-store
 
       - name: Upload artifact
         uses: actions/upload-artifact@v2