diff --git a/README.md b/README.md
index 8af7c9bce8..a4174ca85e 100644
--- a/README.md
+++ b/README.md
@@ -266,6 +266,7 @@ val reads = ac.loadAlignments(
 // Generate, count and sort 21-mers
 val kmers =
   reads
+    .rdd
     .flatMap(_.getSequence.sliding(21).map(k => (k, 1L)))
     .reduceByKey(_ + _)
     .map(_.swap)