diff --git a/usr.bin/top/machine.c b/usr.bin/top/machine.c
--- a/usr.bin/top/machine.c
+++ b/usr.bin/top/machine.c
@@ -1567,9 +1567,12 @@
 	compare_ivcsw,
 	compare_jid,
 	compare_swap,
+	compare_pid,
 	NULL
 };
 
+_Static_assert(nitems(compares) == nitems(ordernames),
+    "ordernames maps into compares, they must have the same # elements");
 
 static int
 swapmode(int *retavail, int *retfree)