diff --git a/core/src/main/scala/spark/api/python/PythonRDD.scala b/core/src/main/scala/spark/api/python/PythonRDD.scala
index 276035a9ad..0138b22d38 100644
--- a/core/src/main/scala/spark/api/python/PythonRDD.scala
+++ b/core/src/main/scala/spark/api/python/PythonRDD.scala
@@ -138,6 +138,7 @@ private class PairwiseRDD(prev: RDD[Array[Byte]]) extends
       case Seq(a, b) => (a, b)
       case x          => throw new Exception("PairwiseRDD: unexpected value: " + x)
     }
+  override def checkpoint() { }
   val asJavaPairRDD : JavaPairRDD[Array[Byte], Array[Byte]] = JavaPairRDD.fromRDD(this)
 }