diff --git a/character-set-and-collation.md b/character-set-and-collation.md
index 0564680453b91..95df06e87205f 100644
--- a/character-set-and-collation.md
+++ b/character-set-and-collation.md
@@ -552,7 +552,7 @@ INSERT INTO t VALUES ('a');
 ```
 
 ```sql
-ERROR 1062 (23000): Duplicate entry 'a' for key 't.PRIMARY' # TiDB is compatible with the case-insensitive collation of MySQL.
+ERROR 1062 (23000): Duplicate entry 'a' for key 't.PRIMARY' -- TiDB is compatible with the case-insensitive collation of MySQL.
 ```
 
 ```sql
@@ -560,7 +560,7 @@ INSERT INTO t VALUES ('a ');
 ```
 
 ```sql
-ERROR 1062 (23000): Duplicate entry 'a ' for key 't.PRIMARY' # TiDB modifies the `PADDING` behavior to be compatible with MySQL.
+ERROR 1062 (23000): Duplicate entry 'a ' for key 't.PRIMARY' -- TiDB modifies the `PADDING` behavior to be compatible with MySQL.
 ```
 
 > **Note:**