diff --git a/packages/vitest/src/node/plugins/cssEnabler.ts b/packages/vitest/src/node/plugins/cssEnabler.ts
index 3c3dc3d116bb..6afa2548737b 100644
--- a/packages/vitest/src/node/plugins/cssEnabler.ts
+++ b/packages/vitest/src/node/plugins/cssEnabler.ts
@@ -28,7 +28,7 @@ export function CSSEnablerPlugin(ctx: Vitest): VitePlugin {
       if (!isCSS(id))
         return
       if (!shouldProcessCSS(id))
-        return ''
+        return { code: '' }
     },
   }
 }