diff --git a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java
index 8d596f87d213..ccf76643db2b 100644
--- a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java
+++ b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java
@@ -522,7 +522,7 @@ public long spill() throws IOException {
           // is accessing the current record. We free this page in that caller's next loadNext()
           // call.
           for (MemoryBlock page : allocatedPages) {
-            if (!loaded || page.getBaseObject() != upstream.getBaseObject()) {
+            if (!loaded || page.pageNumber != ((UnsafeInMemorySorter.SortedIterator)upstream).getCurrentPageNumber()) {
               released += page.size();
               freePage(page);
             } else {
diff --git a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java
index 78da38927878..30d0f3006a04 100644
--- a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java
+++ b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeInMemorySorter.java
@@ -248,6 +248,7 @@ public final class SortedIterator extends UnsafeSorterIterator implements Clonea
     private long baseOffset;
     private long keyPrefix;
     private int recordLength;
+    private long currentPageNumber;
 
     private SortedIterator(int numRecords, int offset) {
       this.numRecords = numRecords;
@@ -262,6 +263,7 @@ public SortedIterator clone() {
       iter.baseOffset = baseOffset;
       iter.keyPrefix = keyPrefix;
       iter.recordLength = recordLength;
+      iter.currentPageNumber = currentPageNumber;
       return iter;
     }
 
@@ -279,6 +281,7 @@ public boolean hasNext() {
     public void loadNext() {
       // This pointer points to a 4-byte record length, followed by the record's bytes
       final long recordPointer = array.get(offset + position);
+      currentPageNumber = memoryManager.decodePageNumber(recordPointer);
       baseObject = memoryManager.getPage(recordPointer);
       baseOffset = memoryManager.getOffsetInPage(recordPointer) + 4;  // Skip over record length
       recordLength = Platform.getInt(baseObject, baseOffset - 4);
@@ -292,6 +295,10 @@ public void loadNext() {
     @Override
     public long getBaseOffset() { return baseOffset; }
 
+    public long getCurrentPageNumber() {
+      return currentPageNumber;
+    }
+
     @Override
     public int getRecordLength() { return recordLength; }