diff --git a/.github/workflows/security-nightly.yml b/.github/workflows/security-nightly.yml
index b3bf294..8de9763 100644
--- a/.github/workflows/security-nightly.yml
+++ b/.github/workflows/security-nightly.yml
@@ -63,7 +63,7 @@ jobs:
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          PINNED=$(grep -oP 'lua-resty-maxminddb \K[0-9.]+' docker/Dockerfile)
+          PINNED=$(grep -oP 'lua-resty-maxminddb=\K[0-9.]+' docker/Dockerfile)
           LATEST=$(gh api repos/anjia0532/lua-resty-maxminddb/releases/latest --jq '.tag_name | ltrimstr("v")')
           echo "Pinned: $PINNED  Latest: $LATEST"
           if [ "$PINNED" != "$LATEST" ]; then