diff --git a/source/ubl-settings-usergroups.c b/source/ubl-settings-usergroups.c
index abe76f7..75af699 100644
--- a/source/ubl-settings-usergroups.c
+++ b/source/ubl-settings-usergroups.c
@@ -2288,9 +2288,11 @@ void on_parameter_changed(GtkWidget *self,ubl_settings_usergroups_user_window *w
 	!yon_char_is_empty(do_not_check)?" ":"",
 	yon_char_return_if_exist(no_user_group,""),
 	NULL);
-	if (final_string[strlen(final_string)-1]==' ') final_string[strlen(final_string)-1]='\0';
-	gtk_entry_set_text(GTK_ENTRY(window->userExtraOptionsEntry),final_string);
-	free(final_string);
+	if (strlen(final_string)){
+		if (final_string[strlen(final_string)-1]==' ') final_string[strlen(final_string)-1]='\0';
+		gtk_entry_set_text(GTK_ENTRY(window->userExtraOptionsEntry),final_string);
+		free(final_string);
+	}
 }
 
 void on_remove_expired(GtkWidget *self, GtkEntryIconPosition icon_pos, GdkEvent *event, GtkEntry *target){