diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/ExpressionEncoder.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/ExpressionEncoder.scala
index d019924711e3..589e215c55e4 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/ExpressionEncoder.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/encoders/ExpressionEncoder.scala
@@ -251,11 +251,6 @@ case class ExpressionEncoder[T](
    */
   def isSerializedAsStruct: Boolean = objSerializer.dataType.isInstanceOf[StructType]
 
-  /**
-   * Returns true if the type `T` is an `Option` type.
-   */
-  def isOptionType: Boolean = classOf[Option[_]].isAssignableFrom(clsTag.runtimeClass)
-
   /**
    * If the type `T` is serialized as a struct, when it is encoded to a Spark SQL row, fields in
    * the struct are naturally mapped to top-level columns in a row. In other words, the serialized
@@ -263,7 +258,9 @@ case class ExpressionEncoder[T](
    * flattened to top-level row, because in Spark SQL top-level row can't be null. This method
    * returns true if `T` is serialized as struct and is not `Option` type.
    */
-  def isSerializedAsStructForTopLevel: Boolean = isSerializedAsStruct && !isOptionType
+  def isSerializedAsStructForTopLevel: Boolean = {
+    isSerializedAsStruct && !classOf[Option[_]].isAssignableFrom(clsTag.runtimeClass)
+  }
 
   // serializer expressions are used to encode an object to a row, while the object is usually an
   // intermediate value produced inside an operator, not from the output of the child operator. This