diff --git a/share/sgml/man-refs.ent b/share/sgml/man-refs.ent
index bd8606617f..4d81da939d 100644
--- a/share/sgml/man-refs.ent
+++ b/share/sgml/man-refs.ent
@@ -3666,6 +3666,7 @@
 <!ENTITY man.ti.4 "<citerefentry/<refentrytitle/ti/<manvolnum/4//">
 <!ENTITY man.tl.4 "<citerefentry/<refentrytitle/tl/<manvolnum/4//">
 <!ENTITY man.trm.4 "<citerefentry/<refentrytitle/trm/<manvolnum/4//">
+<!ENTITY man.trunk.4 "<citerefentry/<refentrytitle/trunk/<manvolnum/4//">
 <!ENTITY man.ttcp.4 "<citerefentry/<refentrytitle/ttcp/<manvolnum/4//">
 <!ENTITY man.tty.4 "<citerefentry/<refentrytitle/tty/<manvolnum/4//">
 <!ENTITY man.tun.4 "<citerefentry/<refentrytitle/tun/<manvolnum/4//">