diff --git a/core/src/main/scala/spark/RDD.scala b/core/src/main/scala/spark/RDD.scala
index d28f3593fe62d85df86be50540c847941186baa8..b413ee21c924012bc82393895e7f35e4e73909a4 100644
--- a/core/src/main/scala/spark/RDD.scala
+++ b/core/src/main/scala/spark/RDD.scala
@@ -68,6 +68,8 @@ abstract class RDD[T: ClassManifest](@transient sc: SparkContext) extends Serial
   def preferredLocations(split: Split): Seq[String] = Nil
   
   def context = sc
+
+  def manifest: ClassManifest[T] = classManifest[T]
   
   // Get a unique ID for this RDD
   val id = sc.newRddId()