diff --git a/src/headerFieldFactory.cpp b/src/headerFieldFactory.cpp
index 807ffe4d..01258d85 100644
--- a/src/headerFieldFactory.cpp
+++ b/src/headerFieldFactory.cpp
@@ -55,6 +55,7 @@ headerFieldFactory::headerFieldFactory()
 	registerName <messageIdField>(vmime::fields::CONTENT_ID);
 	registerName <messageIdField>(vmime::fields::MESSAGE_ID);
 	registerName <defaultField>(vmime::fields::CONTENT_LOCATION);
+	registerName <messageIdField>(vmime::fields::IN_REPLY_TO);
 }