diff --git a/server/src/main/java/io/druid/client/cache/MemcachedOperationQueueFactory.java b/server/src/main/java/io/druid/client/cache/MemcachedOperationQueueFactory.java
index 6f765a5ab28..8118d869731 100644
--- a/server/src/main/java/io/druid/client/cache/MemcachedOperationQueueFactory.java
+++ b/server/src/main/java/io/druid/client/cache/MemcachedOperationQueueFactory.java
@@ -41,8 +41,8 @@ public class MemcachedOperationQueueFactory implements OperationQueueFactory
       @Override
       public long getBytesSize(Operation operation)
       {
-        return operation.getBuffer().capacity();
+        return operation.getBuffer().remaining();
       }
     };
   }
-}
\ No newline at end of file
+}