diff --git a/unity-project/action.yaml b/unity-project/action.yaml
index 95310d5..ca3c622 100644
--- a/unity-project/action.yaml
+++ b/unity-project/action.yaml
@@ -45,7 +45,7 @@ runs:
     with:
       platform: ${{ inputs.platform }}
   - name: "Restore the cached Library folder."
-    if: ${{ inputs.cacheVolume }}
+    if: inputs.cacheVolume != null
     uses: act/common/docker/docker-cp@master
     with:
       volume: ${{ inputs.cacheVolume }}
@@ -61,7 +61,7 @@ runs:
       command: -projectPath ${{ inputs.projectPath }} -buildTarget ${{ steps.getTarget.outputs.buildTarget }} ${{ inputs.command }}
       removeContainer: ${{ inputs.removeContainer }}
   - name: "Cache the Library folder."
-    if: ${{ inputs.cacheVolume }}
+    if: inputs.cacheVolume != null
     uses: act/common/docker/docker-cp@master
     with:
       recreateVolume: false