diff --git a/runtime/doc/spell.txt b/runtime/doc/spell.txt
index 872f251..3e20380 100644
--- a/runtime/doc/spell.txt
+++ b/runtime/doc/spell.txt
@@ -131,8 +131,8 @@
 			rare as this is a fairly uncommon command and all
 			intuitive commands for this are already taken. If you
 			want you can add mappings with e.g.: >
-		nnoremap z?  :exe ':spellrare  ' . expand('<cWORD>')<CR>
-		nnoremap z/  :exe ':spellrare! ' . expand('<cWORD>')<CR>
+		nnoremap z?  :exe ':spellrare  ' .. expand('<cWORD>')<CR>
+		nnoremap z/  :exe ':spellrare! ' .. expand('<cWORD>')<CR>
 <			|:spellundo|, |zuw|, or |zuW| can be used to undo this.
 
 :spellr[rare]! {word}	Add {word} as a rare word to the internal word