diff --git a/action.yml b/action.yml
index bd302e1..c9e939a 100644
--- a/action.yml
+++ b/action.yml
@@ -31,7 +31,7 @@ runs:
 
     - name: Create Cache Key
       run: |
-        normalized_list=$(${{ inputs.packages }} | sed 's/[\s,]+/ /g' | sort)
+        normalized_list=$(echo ${{ inputs.packages }} | sed 's/[\s,]+/ /g' | sort)
         value=$(echo $normalized_list @ ${{ inputs.version }})
         echo "CACHE_KEY=$(echo value | md5sum | /bin/cut -f1 -d' ')" >> $GITHUB_ENV
       shell: bash