diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index be35b4fb..e252e3ff 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -5,6 +5,12 @@ on:
     branches: "*"
   pull_request:
     branches: master
+  workflow_dispatch:
+
+# Cancel redundant in-progress workflow runs.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   test: