diff --git a/src/roster_window.py b/src/roster_window.py
index b0508aecb..98fa0906b 100644
--- a/src/roster_window.py
+++ b/src/roster_window.py
@@ -3821,6 +3821,8 @@ class RosterWindow:
 		if type2 == 'self_contact':
 			return 1
 		if type1 == 'group':
+			name1 = model[iter1][C_JID]
+			name2 = model[iter2][C_JID]
 			if name1 == _('Transports'):
 				return 1
 			if name2 == _('Transports'):