diff --git a/sys/man/4/ptrap b/sys/man/4/ptrap
index 570cce83a..5c29956ad 100644
--- a/sys/man/4/ptrap
+++ b/sys/man/4/ptrap
@@ -1,6 +1,8 @@
 .TH PTRAP 4
 .SH NAME
-ptrap \- \fIplumber\fR(4) filter
+ptrap \-
+.IR plumber (4)
+filter
 .SH SYNOPSIS
 .B ptrap
 .I port