diff --git a/lib/libnetgraph/netgraph.3 b/lib/libnetgraph/netgraph.3
index f51c5150704c..53a2b5f6408a 100644
--- a/lib/libnetgraph/netgraph.3
+++ b/lib/libnetgraph/netgraph.3
@@ -260,7 +260,8 @@ KLD modules must have been loaded via
 returns the previous debug setting.
 .Fn NgSetErrLog
 has no return value.
-All other functions return -1 if there was an error and set errno
+All other functions return \-1 if there was an error and set
+.Va errno
 accordingly.
 A return value of zero from
 .Fn NgRecvMsg