diff --git a/src/System.Private.ServiceModel/src/System/ServiceModel/Dispatcher/XmlSerializerOperationFormatter.cs b/src/System.Private.ServiceModel/src/System/ServiceModel/Dispatcher/XmlSerializerOperationFormatter.cs
index 334921f2a25..165ada07cd2 100644
--- a/src/System.Private.ServiceModel/src/System/ServiceModel/Dispatcher/XmlSerializerOperationFormatter.cs
+++ b/src/System.Private.ServiceModel/src/System/ServiceModel/Dispatcher/XmlSerializerOperationFormatter.cs
@@ -387,7 +387,7 @@ private void SerializeBody(XmlDictionaryWriter writer, MessageVersion version, X
             }
 
             string encoding = _isEncoded ? GetEncoding(version.Envelope) : null;
-            serializer.Serialize(writer, bodyParameters, null);
+            serializer.Serialize(writer, bodyParameters, null, encoding);
         }