diff --git a/streaming/src/main/scala/spark/streaming/DStream.scala b/streaming/src/main/scala/spark/streaming/DStream.scala
index d94548a4f3e291e4c316585667ae10dbfd0a00f5..fbe3cebd6de92197de98898eee6a14d22ce2dce6 100644
--- a/streaming/src/main/scala/spark/streaming/DStream.scala
+++ b/streaming/src/main/scala/spark/streaming/DStream.scala
@@ -547,10 +547,10 @@ abstract class DStream[T: ClassManifest] (
   /**
    * Returns a new DStream which computed based on tumbling window on this DStream.
    * This is equivalent to window(batchTime, batchTime).
-   * @param batchTime tumbling window duration; must be a multiple of this DStream's
+   * @param batchDuration tumbling window duration; must be a multiple of this DStream's
    *                  batching interval
    */
-  def tumble(batchTime: Duration): DStream[T] = window(batchTime, batchTime)
+  def tumble(batchDuration: Duration): DStream[T] = window(batchDuration, batchDuration)
 
   /**
    * Returns a new DStream in which each RDD has a single element generated by reducing all