diff --git a/src/content/content-manager.cpp b/src/content/content-manager.cpp
index ce6fe3545..5d6c66139 100644
--- a/src/content/content-manager.cpp
+++ b/src/content/content-manager.cpp
@@ -94,7 +94,9 @@ Content ContentManager::contentListToMultipart (const list<Content> &contents) {
 
 	Content content;
 	content.setBody(desc);
-	content.setContentType(ContentType::Multipart);
+	ContentType contentType = ContentType::Multipart;
+	contentType.setParameter("boundary=" + boundary);
+	content.setContentType(contentType);
 
 	belle_sip_free(desc);
 	belle_sip_object_unref(mpbh);