diff --git a/coreapi/chat_file_transfer.c b/coreapi/chat_file_transfer.c
index 11394d6ca..74cd69230 100644
--- a/coreapi/chat_file_transfer.c
+++ b/coreapi/chat_file_transfer.c
@@ -491,6 +491,11 @@ int linphone_chat_room_upload_file(LinphoneChatMessage *msg) {
 	belle_http_request_listener_callbacks_t cbs = {0};
 	int err;
 	
+	if (msg->http_request){
+		ms_error("linphone_chat_room_upload_file(): there is already an upload in progress.");
+		return -1;
+	}
+	
 	cbs.process_response = linphone_chat_message_process_response_from_post_file;
 	cbs.process_io_error = linphone_chat_message_process_io_error_upload;
 	cbs.process_auth_requested = linphone_chat_message_process_auth_requested_upload;
@@ -505,6 +510,10 @@ int linphone_chat_message_download_file(LinphoneChatMessage *msg) {
 	belle_http_request_listener_callbacks_t cbs = {0};
 	int err;
 	
+	if (msg->http_request){
+		ms_error("linphone_chat_message_download_file(): there is already a download in progress");
+		return -1;
+	}
 	cbs.process_response_headers = linphone_chat_process_response_headers_from_get_file;
 	cbs.process_response = linphone_chat_process_response_from_get_file;
 	cbs.process_io_error = linphone_chat_message_process_io_error_download;
diff --git a/coreapi/linphonecore.h b/coreapi/linphonecore.h
index 56ebcb397..d5c7d5f74 100644
--- a/coreapi/linphonecore.h
+++ b/coreapi/linphonecore.h
@@ -929,7 +929,7 @@ LINPHONE_PUBLIC int linphone_call_get_stream_count(LinphoneCall *call);
  * @param call
  * @param stream_index
  *
- * @return MsAudio if stream_index = 0, MsVideo otherwise
+ * @return the type (MSAudio, MSVideo, MSText) of the stream of given index.
 **/
 LINPHONE_PUBLIC MSFormatType linphone_call_get_stream_type(LinphoneCall *call, int stream_index);