diff --git a/.hgtags b/.hgtags
index 137219d5a111..9da3c08cec1c 100644
--- a/.hgtags
+++ b/.hgtags
@@ -5085,3 +5085,4 @@ e2cb3d9c8cfc18acad7f77add351416dc95b67c4 FIREFOX_128_3_0esr_BUILD1
 e2cb3d9c8cfc18acad7f77add351416dc95b67c4 FIREFOX_128_3_0esr_RELEASE
 e0c969a3bfc0a23219384269e5b36a589c8f6cc5 FIREFOX_128_3_1esr_BUILD1
 e0c969a3bfc0a23219384269e5b36a589c8f6cc5 FIREFOX_128_3_1esr_RELEASE
+c4a5d008ee64fab523384408fa2868e2d028025d FIREFOX_128_4_0esr_BUILD1