diff --git a/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapStage.scala b/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapStage.scala
index 66c75f325fcde78f0c678188114ef2f7d6839935..48d8d8e9c4b7826a3d7d111972abb59c3e9066fe 100644
--- a/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapStage.scala
+++ b/core/src/main/scala/org/apache/spark/scheduler/ShuffleMapStage.scala
@@ -37,7 +37,7 @@ private[spark] class ShuffleMapStage(
 
   override def toString: String = "ShuffleMapStage " + id
 
-  var numAvailableOutputs: Long = 0
+  var numAvailableOutputs: Int = 0
 
   def isAvailable: Boolean = numAvailableOutputs == numPartitions