diff --git a/sql/core/src/main/scala/org/apache/spark/sql/streaming/progress.scala b/sql/core/src/main/scala/org/apache/spark/sql/streaming/progress.scala
index 3000c4233cfb..cedc1dce4a70 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/streaming/progress.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/streaming/progress.scala
@@ -55,6 +55,8 @@ class StateOperatorProgress private[sql](
     ("numRowsUpdated" -> JInt(numRowsUpdated)) ~
     ("memoryUsedBytes" -> JInt(memoryUsedBytes))
   }
+
+  override def toString: String = prettyJson
 }
 
 /**