diff --git a/gtk/main.c b/gtk/main.c
index 161aa9593..7f4bc4721 100644
--- a/gtk/main.c
+++ b/gtk/main.c
@@ -816,7 +816,7 @@ static void linphone_gtk_update_call_buttons(LinphoneCall *call){
 	conf_frame=(GtkWidget *)g_object_get_data(G_OBJECT(mw),"conf_frame");
 	if(conf_frame==NULL){
 		linphone_gtk_enable_transfer_button(lc,call_list_size>1);
-		linphone_gtk_enable_conference_button(lc,call_list_size>0);
+		linphone_gtk_enable_conference_button(lc,call_list_size>1);
 	} else {
 		linphone_gtk_enable_transfer_button(lc,FALSE);
 		linphone_gtk_enable_conference_button(lc,FALSE);