diff --git a/.github/workflows/build-pull-request.yml b/.github/workflows/build-pull-request.yml
index 4ff842ed..964add54 100644
--- a/.github/workflows/build-pull-request.yml
+++ b/.github/workflows/build-pull-request.yml
@@ -4,6 +4,10 @@ on:
   pull_request:
     types: ['opened', 'synchronize']
 
+concurrency:
+  group: ${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   build-pull-request:
     name: Build pull request
diff --git a/.github/workflows/docker-pr.yml b/.github/workflows/docker-pr.yml
index 997aba6d..24b9389c 100644
--- a/.github/workflows/docker-pr.yml
+++ b/.github/workflows/docker-pr.yml
@@ -6,6 +6,10 @@ on:
       - 'Dockerfile'
       - '.github/workflows/docker-pr.yml'
 
+concurrency:
+  group: ${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   docker-build:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/lockfile.yml b/.github/workflows/lockfile.yml
index a9cc1a34..e96d2818 100644
--- a/.github/workflows/lockfile.yml
+++ b/.github/workflows/lockfile.yml
@@ -5,6 +5,10 @@ on:
     paths:
       - 'package-lock.json'
 
+concurrency:
+  group: ${{ github.workflow }}-pr-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
 jobs:
   lockfile_changes:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/rat-dev-preview.yml b/.github/workflows/rat-dev-preview.yml
index 45da8bc4..47f22b7e 100644
--- a/.github/workflows/rat-dev-preview.yml
+++ b/.github/workflows/rat-dev-preview.yml
@@ -4,6 +4,13 @@ on:
   push:
     branches: ['dev']
 
+# One run per ref wins: a newer push to dev cancels the older queued or running one, so the run
+# that builds rat-dev-dist is always the newest. Pull-request runs are other workflows and other
+# groups; they never cancel it.
+concurrency:
+  group: rat-dev-preview
+  cancel-in-progress: true
+
 jobs:
   build:
     name: Build dev preview