diff --git a/runtime/autoload/dist/ft.vim b/runtime/autoload/dist/ft.vim
index 48eaf3f..d5c21ac 100644
--- a/runtime/autoload/dist/ft.vim
+++ b/runtime/autoload/dist/ft.vim
@@ -145,7 +145,7 @@
     return
   endif
 
-  if getline(1) =~ '^%'
+  if getline(1) =~ '^\v%(\%|\\)'
     setf tex
   elseif getline(1)[0] == '#' && getline(1) =~ 'rexx'
     setf rexx