diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index 356323c..3bd14e3 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -26,9 +26,7 @@ jobs:
       - name: Get version
         id: version
         shell: bash
-        run: |
-          v=${GITHUB_REF#refs/tags/v}
-          echo ::set-output name=VERSION::${v:-0.0.0}
+        run: echo ::set-output name=VERSION::"$([[ "$GITHUB_REF" == refs/tags/v* ]] && echo ${GITHUB_REF#refs/tags/v} || echo '0.0.0')"
       # Install Ruby manually as actions/setup-ruby@v1 does not compile with `--enable-shared`.
       - name: Prepare for rbenv
         run: |
@@ -95,9 +93,7 @@ jobs:
       - name: Get version
         id: version
         shell: bash
-        run: |
-          v=${GITHUB_REF#refs/tags/v}
-          echo ::set-output name=VERSION::${v:-0.0.0}
+        run: echo ::set-output name=VERSION::"$([[ "$GITHUB_REF" == refs/tags/v* ]] && echo ${GITHUB_REF#refs/tags/v} || echo '0.0.0')"
       - name: Set up Ruby
         uses: actions/setup-ruby@v1
         with: