diff --git a/sway/behaviours b/sway/behaviours
index d56f4cae6..75ce0a294 100644
--- a/sway/behaviours
+++ b/sway/behaviours
@@ -7,9 +7,11 @@
 assign [class="Mattermost"] 1
 assign [class="Rocket.Chat"] 1
 assign [class="UXTerm"] grave
+assign [class="Thunderbird"] 2
 assign [app_id="thunderbird"] 2
 assign [class="Chromium"] 3
 assign [class="Linphone"] 5
+assign [class="firefox"] 7
 assign [app_id="firefox"] 7
 assign [app_id="com.github.gittyup.Gittyup"] 9