diff --git a/.github/workflows/build-shit.yml b/.github/workflows/build-shit.yml
index e217d1f18..4d674f025 100644
--- a/.github/workflows/build-shit.yml
+++ b/.github/workflows/build-shit.yml
@@ -3,6 +3,10 @@ on:
   workflow_dispatch:
   push:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   create-nightly-html5:
     runs-on: [self-hosted, linux]
diff --git a/.github/workflows/cancel-merged-branches.yml b/.github/workflows/cancel-merged-branches.yml
new file mode 100644
index 000000000..b9b66834b
--- /dev/null
+++ b/.github/workflows/cancel-merged-branches.yml
@@ -0,0 +1,35 @@
+name: cancel-merged-branches
+on:
+  pull_request:
+    types:
+      - closed
+  push:
+
+jobs:
+  cancel_stuff:
+    if: github.event.pull_request.merged == true
+    runs-on: ubuntu-latest
+    permissions:
+      actions: write
+    steps:
+      - uses: actions/github-script@v7
+        id: cancel-runs
+        with:
+          result-encoding: string
+          retries: 3
+          script: |
+            let branch_workflows = await github.rest.actions.listWorkflowRuns({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              workflow_id: "build-shit.yml",
+              status: "queued",
+              branch: "${{ github.ref_name }}"
+            });
+            let runs = branch_workflows.data.workflow_runs;
+            runs.forEach((run) => {
+              github.rest.actions.cancelWorkflowRun({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                run_id: run.id
+              });
+            });