diff --git a/gluten-data/src/main/scala/org/apache/spark/sql/catalyst/expressions/ToStringUtil.scala b/gluten-data/src/main/scala/org/apache/spark/sql/catalyst/expressions/ToStringUtil.scala
index 272800aed1aa7..0b92191217d3f 100644
--- a/gluten-data/src/main/scala/org/apache/spark/sql/catalyst/expressions/ToStringUtil.scala
+++ b/gluten-data/src/main/scala/org/apache/spark/sql/catalyst/expressions/ToStringUtil.scala
@@ -148,5 +148,5 @@ case class ToStringUtil(timeZoneId: Option[String] = None)
     throw new UnsupportedOperationException()
   }
 
-  override def child : Expression = null
+  override def child: Expression = null
 }