diff --git a/core/src/main/scala/org/apache/spark/storage/memory/MemoryStore.scala b/core/src/main/scala/org/apache/spark/storage/memory/MemoryStore.scala
index 9b636338ff2ed6e96d1ef7d55d0dc254329561d9..31445eced248c7a16d7d3aabc497a14ffe105b00 100644
--- a/core/src/main/scala/org/apache/spark/storage/memory/MemoryStore.scala
+++ b/core/src/main/scala/org/apache/spark/storage/memory/MemoryStore.scala
@@ -21,9 +21,9 @@ import java.io.OutputStream
 import java.nio.ByteBuffer
 import java.util.LinkedHashMap
 
+import scala.collection.SortedMap
 import scala.collection.mutable
 import scala.collection.mutable.ArrayBuffer
-import scala.collection.SortedMap
 import scala.reflect.ClassTag
 
 import com.google.common.io.ByteStreams
@@ -92,7 +92,7 @@ private[spark] class MemoryStore(
   private class OurBlockIdAndSizeType(
       private var blockId: BlockId,
       private var size: Long) extends Ordering[OurBlockIdAndSizeType] {
-    def compare(other: OurBlockIdAndSizeType): Int = this.size compare other.size
+    def compare(other: OurBlockIdAndSizeType): Int = compare(this.size, other.size)
   }
 
   private val entries = new LinkedHashMap[BlockId, MemoryEntry[_]](32, 0.75f, true)