diff --git a/autoload/matchup/ts_engine.vim b/autoload/matchup/ts_engine.vim
index 99eedb2..07d425b 100644
--- a/autoload/matchup/ts_engine.vim
+++ b/autoload/matchup/ts_engine.vim
@@ -27,7 +27,7 @@ function! matchup#ts_engine#attach(bufnr, lang) abort
   let s:attached[a:bufnr] = a:lang
 endfunction
 
-function! matchup#ts_engine#detach(bufnr, lang) abort
+function! matchup#ts_engine#detach(bufnr) abort
   unlet s:attached[a:bufnr]
 endfunction