diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index 43445d1..8bb57fd 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -28,6 +28,10 @@ jobs:
     steps:
       - uses: https://data.forgejo.org/actions/checkout@v4
 
+      # Debugging cache miss issue (#16) — check whether ACTIONS_CACHE_URL is injected
+      - name: Debug cache env
+        run: echo "ACTIONS_CACHE_URL=${ACTIONS_CACHE_URL}" && env | grep -i cache || true
+
       - name: Cache PHP installation
         uses: https://data.forgejo.org/actions/cache@v4
         with: