diff --git a/share/examples/bhyve/vmrun.sh b/share/examples/bhyve/vmrun.sh
--- a/share/examples/bhyve/vmrun.sh
+++ b/share/examples/bhyve/vmrun.sh
@@ -351,7 +351,12 @@
 	i=0
 	while [ $i -lt $pass_total ] ; do
 	    eval "pass=\$pass_dev${i}"
-	    devargs="$devargs -s $nextslot:0,passthru,${pass} "
+	    passno="$(
+		pciconf -l | grep "${pass}@" | awk '{print $1}' | cut -f2 -d@ |
+		cut -f2- -d: | sed 's/:$//' | tr : /
+	    )"
+	    test -z "${passno}" && errmsg "${pass} is not a host PCI device"
+	    devargs="$devargs -s $nextslot:0,passthru,${passno} "
 	    nextslot=$(($nextslot + 1))
 	    i=$(($i + 1))
         done