diff --git a/misc/factor.vim.fgen b/misc/factor.vim.fgen
index 57a518ae11..0d446420cc 100644
--- a/misc/factor.vim.fgen
+++ b/misc/factor.vim.fgen
@@ -317,4 +317,4 @@ endif
 
 let b:current_syntax = "factor"
 
-" vim: syntax=vim
+" vim:set ft=vim sw=4:
diff --git a/misc/vim/syntax/factor.vim b/misc/vim/syntax/factor.vim
index df4e249af2..8e827368b7 100644
--- a/misc/vim/syntax/factor.vim
+++ b/misc/vim/syntax/factor.vim
@@ -304,4 +304,4 @@ endif
 
 let b:current_syntax = "factor"
 
-" vim: syntax=vim
+" vim:set ft=vim sw=4: