diff --git a/lib/libc/gen/sysctl.3 b/lib/libc/gen/sysctl.3
index 53a6f3724da..c9e002cbebf 100644
--- a/lib/libc/gen/sysctl.3
+++ b/lib/libc/gen/sysctl.3
@@ -540,7 +540,7 @@ The fifth and sixth level names are as follows:
 .It Sy "Fifth level name	Sixth level is:"
 .It "NET\_RT\_FLAGS	rtflags"
 .It "NET\_RT\_DUMP	None"
-.It "NET\_RT\_IFLIST	None"
+.It "NET\_RT\_IFLIST	0 or if_index"
 .El
 .It Li PF_INET
 Get or set various global information about the IPv4