diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0c3643b1..abe01651 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,6 +14,10 @@ on:
       - 'janitor/**'
   workflow_dispatch:  # to allow manual re-runs
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 env:
   UV_VERSION: 0.4.16
 
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 9edba483..016ff0c3 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -15,6 +15,10 @@ on:
   schedule:
     - cron: '44 17 * * 3'
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   analyze:
     name: Analyze