diff --git a/.github/workflows/checkfmt.yml b/.github/workflows/checkfmt.yml
new file mode 100644
index 0000000..077ec5d
--- /dev/null
+++ b/.github/workflows/checkfmt.yml
@@ -0,0 +1,46 @@
+name: Check the format of a PR
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - ready_for_review
+      - labeled
+env:
+  USER: runner
+
+# Cancel the current workflow when new commit pushed
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+
+  check-format:
+    name: "Check format"
+    runs-on: [self-hosted, linux, nixos]
+    strategy:
+      fail-fast: false
+    defaults:
+      run:
+        working-directory: ./templates/chisel
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+      - name: "Check Scala format"
+        continue-on-error: true
+        run: |
+          nix develop -c bash -c 'mill -i gcd.checkFormat && mill -i elaborator.checkFormat'
+      - name: "Check Rust format"
+        continue-on-error: true
+        run: |
+          cd gcdemu
+          nix develop -c cargo fmt --check
+          cd ..
+      - name: "Check nix format"
+        continue-on-error: true
+        run: |
+          nix fmt -- --check nix flake.nix
+
diff --git a/templates/chisel/.gitignore b/templates/chisel/.gitignore
index 6f27e13..338f9fc 100644
--- a/templates/chisel/.gitignore
+++ b/templates/chisel/.gitignore
@@ -1,8 +1,17 @@
 .bloop
 .bsp
+.jvm-opts
+.mill-jvm-opts
 .metals/
 .vscode/
+
 out/
 result*
+gcd-sim-result/
 /dependencies/
 target/
+
+*.vcd
+*.fst
+*.fsdb
+*.log
diff --git a/templates/chisel/.scalafmt.conf b/templates/chisel/.scalafmt.conf
index c839f64..0310aaa 100644
--- a/templates/chisel/.scalafmt.conf
+++ b/templates/chisel/.scalafmt.conf
@@ -10,7 +10,7 @@ lineEndings = preserve
 includeCurlyBraceInSelectChains = false
 danglingParentheses.preset = true
 
-align.tokens.add = [
+align.tokens."+" = [
 {
   code = ":"
 }
diff --git a/templates/chisel/build.sc b/templates/chisel/build.sc
index 4da6ed7..3b79023 100644
--- a/templates/chisel/build.sc
+++ b/templates/chisel/build.sc
@@ -37,7 +37,7 @@ trait GCD extends millbuild.common.HasChisel with ScalafmtModule {
 }
 
 object elaborator extends Elaborator
-trait Elaborator extends millbuild.common.ElaboratorModule {
+trait Elaborator extends millbuild.common.ElaboratorModule with ScalafmtModule {
   def scalaVersion = T(deps.scalaVer)
 
   def panamaconverterModule = panamaconverter