diff --git a/man/erb.1 b/man/erb.1
index 46ee2fa2d4..3b350e0064 100644
--- a/man/erb.1
+++ b/man/erb.1
@@ -77,6 +77,8 @@ And leading whitespaces are removed if the erb directive starts with
 .Li "<%-" .
 .Pp
 .El
+.It Fl r
+Load a library
 .Pp
 .It Fl U
 can be one of