diff --git a/CHANGES.txt b/CHANGES.txt
index fc9ec7fcca..430654948a 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -146,7 +146,7 @@ Merged from 2.0:
  * Improve PropertyFileSnitch logging (CASSANDRA-8183)
  * Add DC-aware sequential repair (CASSANDRA-8193)
  * Use live sstables in snapshot repair if possible (CASSANDRA-8312)
-
+ * Fix hints serialized size calculation (CASSANDRA-8587)
 
 2.1.2
  * (cqlsh) parse_for_table_meta errors out on queries with undefined
diff --git a/src/java/org/apache/cassandra/net/MessageOut.java b/src/java/org/apache/cassandra/net/MessageOut.java
index 5193c2bbae..357d798d57 100644
--- a/src/java/org/apache/cassandra/net/MessageOut.java
+++ b/src/java/org/apache/cassandra/net/MessageOut.java
@@ -131,8 +131,8 @@ public class MessageOut<T>
         size += TypeSizes.NATIVE.sizeof(parameters.size());
         for (Map.Entry<String, byte[]> entry : parameters.entrySet())
         {
-            TypeSizes.NATIVE.sizeof(entry.getKey());
-            TypeSizes.NATIVE.sizeof(entry.getValue().length);
+            size += TypeSizes.NATIVE.sizeof(entry.getKey());
+            size += TypeSizes.NATIVE.sizeof(entry.getValue().length);
             size += entry.getValue().length;
         }