diff --git a/samples/demo01.md b/samples/demo01.md
index 343850e..8f77d52 100644
--- a/samples/demo01.md
+++ b/samples/demo01.md
@@ -37,7 +37,7 @@ export_on_save:
 @enduml
 ```
 # 时序图1
-```uml
+```plantuml
 @startuml
 
 !include https://deep-tek.com/puml/core.puml