diff --git a/tidb-limitations.md b/tidb-limitations.md
index b9b9c11988f28..1369fcc929dee 100644
--- a/tidb-limitations.md
+++ b/tidb-limitations.md
@@ -70,8 +70,8 @@ You can adjust the size limit via the [`txn-entry-size-limit`](/tidb-configurati
 
 | Type       | Upper limit   |
 |:----------|:----------|
-| CHAR       | 256 characters      |
-| BINARY     | 256 characters      |
+| CHAR       | 255 characters      |
+| BINARY     | 255 characters      |
 | VARBINARY  | 65535 characters    |
 | VARCHAR    | 16383 characters    |
 | TEXT       | Defaults to 6 MiB and can be adjusted to 120 MiB                |