diff --git a/packages/ui/src/services/config-transport/createProxyComponent.ts b/packages/ui/src/services/config-transport/createProxyComponent.ts
index 1deb856a00..d829d05432 100644
--- a/packages/ui/src/services/config-transport/createProxyComponent.ts
+++ b/packages/ui/src/services/config-transport/createProxyComponent.ts
@@ -88,7 +88,7 @@ const createAttrsWithCustomConfig = (instance: ComponentInternalInstance, propsF
       if (typeof key !== 'string') { return target[key] }
 
       if (key === 'class') {
-        return (normalizeClass(propsFromConfig.value.class) + ' ' + instanceAttrs.class).trim()
+        return normalizeClass([propsFromConfig.value.class, instanceAttrs.class])
       }
 
       if (key === 'style') {