diff --git a/core/src/main/java/org/apache/spark/unsafe/map/BytesToBytesMap.java b/core/src/main/java/org/apache/spark/unsafe/map/BytesToBytesMap.java
index 4fadfe36cd716..7fdcf22c45f73 100644
--- a/core/src/main/java/org/apache/spark/unsafe/map/BytesToBytesMap.java
+++ b/core/src/main/java/org/apache/spark/unsafe/map/BytesToBytesMap.java
@@ -879,6 +879,7 @@ public LongArray getArray() {
    * Reset this map to initialized state.
    */
   public void reset() {
+    updatePeakMemoryUsed();
     numKeys = 0;
     numValues = 0;
     freeArray(longArray);