diff --git a/core/src/main/scala/org/apache/spark/util/collection/ExternalSorter.scala b/core/src/main/scala/org/apache/spark/util/collection/ExternalSorter.scala
index 3136306a3adb..97ddd96c9826 100644
--- a/core/src/main/scala/org/apache/spark/util/collection/ExternalSorter.scala
+++ b/core/src/main/scala/org/apache/spark/util/collection/ExternalSorter.scala
@@ -288,6 +288,7 @@ private[spark] class ExternalSorter[K, V, C](
     myMemoryThreshold = 0
 
     _memoryBytesSpilled += memorySize
+    elementsRead = 0
   }
 
   /**