diff --git a/packages/mermaid/src/docs/.vitepress/theme/Mermaid.vue b/packages/mermaid/src/docs/.vitepress/theme/Mermaid.vue
index 85c13393c..5012d3067 100644
--- a/packages/mermaid/src/docs/.vitepress/theme/Mermaid.vue
+++ b/packages/mermaid/src/docs/.vitepress/theme/Mermaid.vue
@@ -17,7 +17,7 @@ const props = defineProps({
   },
 });
 
-const svg = ref(null);
+const svg = ref('');
 let mut = null;
 
 onMounted(async () => {