diff --git a/doc/asciidoc.conf b/doc/asciidoc.conf
index 92e01179..98308f53 100644
--- a/doc/asciidoc.conf
+++ b/doc/asciidoc.conf
@@ -31,7 +31,13 @@ ifdef::backend-docbook[]
 [listingblock]
 <example><title>{title}</title>
 <literallayout>
+ifdef::doctype-manpage[]
+&#10;.ft C&#10;
+endif::doctype-manpage[]
 |
+ifdef::doctype-manpage[]
+&#10;.ft&#10;
+endif::doctype-manpage[]
 </literallayout>
 {title#}</example>
 endif::backend-docbook[]