diff --git a/ftdetect/rust.vim b/ftdetect/rust.vim
index 1c9b1521..d552b963 100644
--- a/ftdetect/rust.vim
+++ b/ftdetect/rust.vim
@@ -1,6 +1,12 @@
 " vint: -ProhibitAutocmdWithNoGroup
 
-autocmd BufRead,BufNewFile *.rs setf rust
+autocmd BufRead,BufNewFile *.rs call s:set_rust_filetype()
 autocmd BufRead,BufNewFile Cargo.toml setf FALLBACK cfg
 
+function! s:set_rust_filetype() abort
+    if &filetype !=# 'rust'
+        set filetype=rust
+    endif
+endfunction
+
 " vim: set et sw=4 sts=4 ts=8: