diff --git a/.github/workflows/nightly.yaml b/.github/workflows/nightly.yaml
index 3718cc0..ceafc47 100644
--- a/.github/workflows/nightly.yaml
+++ b/.github/workflows/nightly.yaml
@@ -1,4 +1,5 @@
 name: Nightly
+# Note: this job only checks out the dev branch! (see `ref: dev`)
 on:
   schedule:
     - cron: '0 2 * * *'
@@ -9,6 +10,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+        with:
+          ref: dev
 
       - uses: ocaml/setup-ocaml@v3
         with: