diff --git a/samples/dem01.md b/samples/dem01.md
index caac350..15335cd 100644
--- a/samples/dem01.md
+++ b/samples/dem01.md
@@ -11,7 +11,7 @@ export_on_save:
 
 # 时序图
 
-```puml
+```plantuml
 @startuml
 
 !include ../puml/core.puml
@@ -34,7 +34,7 @@ export_on_save:
 
 # 样式
 
-```puml
+```plantuml
 @startuml
 !include ../puml/cerulean/puml-theme-cerulean.puml
 
@@ -69,7 +69,7 @@ public void fun() {
 }
 ```
 # C4图
-```puml
+```plantuml
 @startuml container-diagram
 
 !include ../puml/C4_Component.puml
@@ -111,7 +111,7 @@ Rel_Neighbor(backend_api, banking_system, "Uses", "sync/async, XML/HTTPS")
 
 # 脑图
 
-```puml
+```plantuml
 @startmindmap
 <style>
 mindmapDiagram {