diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index da98dd5f..d4438191 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -7358,7 +7358,7 @@ The substituted value is not rescanned for more output variables;
 occurrences of @samp{@@@var{variable}@@} in the value are inserted
 literally into the output file.  (The algorithm uses the special marker
 @code{|#_!!_#|} internally, so the substituted value cannot contain
-@code{|#_!!_#|})
+@code{|#_!!_#|}.)
 
 If @var{value} is given, in addition assign it to @var{variable}.