diff --git a/share/man/man5/make.conf.5 b/share/man/man5/make.conf.5
index c0f3124a011..99a917fbbeb 100644
--- a/share/man/man5/make.conf.5
+++ b/share/man/man5/make.conf.5
@@ -352,6 +352,9 @@ rather than load the server's kernel.
 .It Va MODULES_OVERRIDE
 .Pq Vt str
 Set to a list of modules to build instead of all of them.
+.It Va PORTS_MODULES
+Set this to the list of ports you wish to rebuild every time the kernel
+is built.
 .It Va NO_KERNELCONFIG
 .Pq Vt bool
 Set this to skip running