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 be382955c0d4..3b1ece4373f4 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
@@ -281,7 +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);
+      currentPageNumber = TaskMemoryManager.decodePageNumber(recordPointer);
       baseObject = memoryManager.getPage(recordPointer);
       baseOffset = memoryManager.getOffsetInPage(recordPointer) + 4;  // Skip over record length
       recordLength = Platform.getInt(baseObject, baseOffset - 4);