diff --git a/.github/workflows/gem.yml b/.github/workflows/gem.yml
index fc3bd48..86dd614 100644
--- a/.github/workflows/gem.yml
+++ b/.github/workflows/gem.yml
@@ -30,7 +30,7 @@ jobs:
       with:
         ruby-version: 2.6.x
     - name: Publish
-      if: github.ref == 'master'
+      if: github.ref == 'refs/heads/master'
       run: |
         mkdir -p $HOME/.gem
         touch $HOME/.gem/credentials