diff --git a/autoload/neosnippet/commands.vim b/autoload/neosnippet/commands.vim
index f80b826..fdb4ab8 100644
--- a/autoload/neosnippet/commands.vim
+++ b/autoload/neosnippet/commands.vim
@@ -137,7 +137,8 @@ function! neosnippet#commands#_clear_markers() "{{{
   let expand_stack = neosnippet#variables#expand_stack()
 
   " Get patterns and count.
-  if empty(expand_stack)
+  if !&l:modifiable
+        \ || empty(expand_stack)
         \ || neosnippet#variables#current_neosnippet().trigger
     return
   endif