diff --git a/runtime/optwin.vim b/runtime/optwin.vim
index 0ace4cc..12e934f 100644
--- a/runtime/optwin.vim
+++ b/runtime/optwin.vim
@@ -373,6 +373,11 @@
   call append("$", "\t(local to window)")
   call <SID>OptionL("nuw")
 endif
+if has("conceal")
+  call append("$", "conceallevel\tcontrols whether concealable elements are hidden")
+  call append("$", "\t(local to window)")
+  call <SID>OptionL("conc")
+endif
 
 
 call <SID>Header("syntax, highlighting and spelling")