diff --git a/lib/NGCP/Schema/Result/rtc_session.pm b/lib/NGCP/Schema/Result/rtc_session.pm
index e12ffd5b..6c430cc0 100644
--- a/lib/NGCP/Schema/Result/rtc_session.pm
+++ b/lib/NGCP/Schema/Result/rtc_session.pm
@@ -38,6 +38,7 @@ __PACKAGE__->add_columns(
     data_type => "varchar",
     is_nullable => 0,
     size => 45,
+    default_value => "",
   },
 );