diff --git a/plugins/gtkgui/config.py b/plugins/gtkgui/config.py
index 31b821b553538d3160b7549409c037ee1f822414..981e6da72d70bf3ef0534595d3d4cb15dbca749d 100644
--- a/plugins/gtkgui/config.py
+++ b/plugins/gtkgui/config.py
@@ -1047,6 +1047,9 @@ class Account_modification_window:
 		priority = self.xml.get_widget('priority_spinbutton').get_value_as_int()
 		new_account_checkbutton = self.xml.get_widget('new_account_checkbutton')
 		name = self.xml.get_widget('name_entry').get_text()
+		if name != self.account and self.plugin.connected[self.account] != 0:
+			Error_dialog(_('You must be offline to change the account\'s name'))
+			return
 		jid = self.xml.get_widget('jid_entry').get_text()
 		autoconnect = 0
 		if self.xml.get_widget('autoconnect_checkbutton').get_active():