diff --git a/core/src/main/scala/spark/storage/DiskStore.scala b/core/src/main/scala/spark/storage/DiskStore.scala
index c1cff255526604fe050f3a28fcfe0a77a6db3921..0af6e4a35917fd8551f15ab6c6d47c391824d4b2 100644
--- a/core/src/main/scala/spark/storage/DiskStore.scala
+++ b/core/src/main/scala/spark/storage/DiskStore.scala
@@ -40,7 +40,7 @@ private class DiskStore(blockManager: BlockManager, rootDirs: String)
     override def open(): DiskBlockObjectWriter = {
       val fos = new FileOutputStream(f, true)
       channel = fos.getChannel()
-      bs = blockManager.wrapForCompression(blockId, new FastBufferedOutputStream(fos))
+      bs = blockManager.wrapForCompression(blockId, new FastBufferedOutputStream(fos, bufferSize))
       objOut = serializer.newInstance().serializeStream(bs)
       initialized = true
       this