diff --git a/lib/app/components/no-ssr.js b/lib/app/components/no-ssr.js
index 9dbc5bcbf5..637e828ab7 100644
--- a/lib/app/components/no-ssr.js
+++ b/lib/app/components/no-ssr.js
@@ -5,24 +5,31 @@
 export default {
   name: 'no-ssr',
   props: ['placeholder'],
-  data () {
+  data() {
     return {
       canRender: false
     }
   },
-  mounted () {
+  mounted() {
     this.canRender = true
   },
-  render (h) {
+  render(h) {
     if (this.canRender) {
       if (
         process.env.NODE_ENV === 'development' &&
+        this.$slots.default &&
         this.$slots.default.length > 1
       ) {
-        throw new Error('<no-ssr> You cannot use multiple child components')
+        throw new Error('[vue-no-ssr] You cannot use multiple child components')
       }
-      return this.$slots.default[0]
+      return this.$slots.default && this.$slots.default[0]
     }
-    return h('div', { class: { 'no-ssr-placeholder': true } }, this.placeholder)
+    return h(
+      'div',
+      {
+        class: ['no-ssr-placeholder']
+      },
+      this.placeholder
+    )
   }
 }