diff --git a/codespell_lib/data/dictionary_rare.txt b/codespell_lib/data/dictionary_rare.txt
index a6e2074c87..a6311e15db 100644
--- a/codespell_lib/data/dictionary_rare.txt
+++ b/codespell_lib/data/dictionary_rare.txt
@@ -16,7 +16,7 @@ bellow->below
 bloc->block
 blocs->blocks
 bodgy->body
-bu->by
+bu->by, be, but, bug, bun, bud, buy, bum,
 buss->bus
 busses->buses
 calculatable->calculable