diff --git a/src/chat/modifier/multipart-chat-message-modifier.cpp b/src/chat/modifier/multipart-chat-message-modifier.cpp
index 4abf91210..243cb32e1 100644
--- a/src/chat/modifier/multipart-chat-message-modifier.cpp
+++ b/src/chat/modifier/multipart-chat-message-modifier.cpp
@@ -59,7 +59,7 @@ ChatMessageModifier::Result MultipartChatMessageModifier::encode (
 	multipartMessage << "--";
 
 	Content newContent;
-	ContentType newContentType("multipart/mixed");
+	ContentType newContentType(ContentType::Multipart);
 	newContentType.setParameter("boundary=" + boundary);
 	newContent.setContentType(newContentType);
 	newContent.setBody(multipartMessage.str());
diff --git a/src/content/content-manager.cpp b/src/content/content-manager.cpp
index 46cc01c28..1381f8dc1 100644
--- a/src/content/content-manager.cpp
+++ b/src/content/content-manager.cpp
@@ -97,7 +97,7 @@ Content ContentManager::contentListToMultipart (const list<Content> &contents) {
 	Content content;
 	content.setBody(desc);
 	ContentType contentType = ContentType::Multipart;
-	contentType.setParameter("boundary=" + boundary);
+	contentType.setParameter("boundary=" + MULTIPART_BOUNDARY);
 	content.setContentType(contentType);
 
 	belle_sip_free(desc);