diff --git a/doc/erd-dsl.md b/doc/erd-dsl.md
index d13c1b0..b87432e 100644
--- a/doc/erd-dsl.md
+++ b/doc/erd-dsl.md
@@ -8,7 +8,7 @@
 
 ## Example
 
-```
+```yaml
 entities:
   user:
     - name: id