diff --git a/action.yml b/action.yml
index 192acef..78c8882 100644
--- a/action.yml
+++ b/action.yml
@@ -31,7 +31,12 @@ runs:
     - name: Run Bundler Audit
       id: audit
       run: |
-        bundle-audit check --update ${${{ inputs.ignore_list }}:+--ignore ${{ inputs.ignore_list }}} > audit_output.txt || true
+        ignore_flag=""
+        if [ -n "${{ inputs.ignore_list }}" ]; then
+          ignore_flag="--ignore ${{ inputs.ignore_list }}"
+        fi
+
+        bundle-audit check --update $ignore_flag > audit_output.txt || true
       shell: bash
 
     - name: Check for Vulnerabilities