diff --git a/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
index 955b42c3baaa..cc5e278e08b8 100644
--- a/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
+++ b/core/src/main/scala/org/apache/spark/rdd/PairRDDFunctions.scala
@@ -993,6 +993,7 @@ class PairRDDFunctions[K, V](self: RDD[(K, V)])
       val (outputMetrics, bytesWrittenCallback) = initHadoopOutputMetrics(context)
 
       val writer = format.getRecordWriter(hadoopContext).asInstanceOf[NewRecordWriter[K,V]]
+      require(writer != null, s"Unable to obtain NewRecordWriter")
       var recordsWritten = 0L
       try {
         while (iter.hasNext) {