diff --git a/docs/guide/input-validation.md b/docs/guide/input-validation.md
index a5f1bccea0..9af27d6218 100644
--- a/docs/guide/input-validation.md
+++ b/docs/guide/input-validation.md
@@ -446,7 +446,7 @@ class EntryForm extends Model
 
 Sometimes validators involve multiple attributes. Consider the following form:
 
-``` php
+```php
 class MigrationForm extends \yii\base\Model
 {
     /**