diff --git a/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/params/CustomParams.scala b/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/params/CustomParams.scala
index 0a411054a..255253fb7 100644
--- a/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/params/CustomParams.scala
+++ b/jvm-packages/xgboost4j-spark/src/main/scala/ml/dmlc/xgboost4j/scala/spark/params/CustomParams.scala
@@ -100,7 +100,6 @@ class TrackerConfParam(
   override def jsonDecode(json: String): TrackerConf = {
     implicit val formats = DefaultFormats
     val parsedValue = parse(json)
-    println(parsedValue.children)
     parsedValue.extract[TrackerConf]
   }
 }