diff --git a/.github/workflows/CompatPrune.yml b/.github/workflows/CompatPrune.yml
new file mode 100644
index 000000000..e1014f216
--- /dev/null
+++ b/.github/workflows/CompatPrune.yml
@@ -0,0 +1,26 @@
+name: CompatPrune
+
+# Monthly audit of the [compat] entries of the control-toolbox packages, from the top of
+# the dependency graph: drops the specifiers no supported Julia version selects (one PR
+# per repository, one tracking issue here). See CTActions/docs/WORKFLOWS.md.
+
+on:
+  schedule:
+    - cron: '0 4 1 * *'
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: 'Only audit and report: no PR, no issue'
+        type: boolean
+        default: true
+
+jobs:
+  call:
+    uses: control-toolbox/CTActions/.github/workflows/compat-prune.yml@main
+    with:
+      # Dry run on every trigger until the GitHub App is set up (CTActions#95); then the
+      # schedule publishes: `github.event_name == 'workflow_dispatch' && inputs.dry_run`.
+      dry_run: ${{ github.event_name != 'workflow_dispatch' || inputs.dry_run }}
+    secrets:
+      CT_APP_CLIENT_ID: ${{ secrets.CT_APP_CLIENT_ID }}
+      CT_APP_PRIVATE_KEY: ${{ secrets.CT_APP_PRIVATE_KEY }}