diff --git a/tools/tools/netrate/pktgen/pktgen.c b/tools/tools/netrate/pktgen/pktgen.c
index ff37b07612ee..ec6f3819f756 100644
--- a/tools/tools/netrate/pktgen/pktgen.c
+++ b/tools/tools/netrate/pktgen/pktgen.c
@@ -95,6 +95,8 @@ struct pktgen {
 	int			pktg_datalen;
 	struct ifnet		*pktg_ifp;
 
+	int			pktg_pktenq;
+
 	struct sockaddr_in	pktg_src;
 	int			pktg_ndst;
 	struct sockaddr_in	*pktg_dst;
@@ -247,7 +249,7 @@ pktgen_config(struct pktgen *pktg, const struct pktgen_conf *conf)
 	const struct sockaddr *sa;
 	struct ifnet *ifp;
 	size_t dst_size;
-	int i, error;
+	int i, error, pktenq;
 
 	if (pktg->pktg_flags & (PKTG_F_RUNNING | PKTG_F_CONFIG))
 		return EBUSY;
@@ -294,6 +296,14 @@ pktgen_config(struct pktgen *pktg, const struct pktgen_conf *conf)
 		goto failed;
 	}
 
+	pktenq = conf->pc_pktenq;
+	if (pktenq < 0 || pktenq > ifp->if_snd.ifq_maxlen) {
+		error = ENOBUFS;
+		goto failed;
+	} else if (pktenq == 0) {
+		pktenq = (ifp->if_snd.ifq_maxlen * 3) / 4;
+	}
+
 	sa = &conf->pc_dst_lladdr;
 	if (sa->sa_family != AF_LINK) {
 		error = EPROTONOSUPPORT;
@@ -316,6 +326,7 @@ pktgen_config(struct pktgen *pktg, const struct pktgen_conf *conf)
 
 	pktg->pktg_duration = conf->pc_duration;
 	pktg->pktg_datalen = conf->pc_datalen;
+	pktg->pktg_pktenq = pktenq;
 	pktg->pktg_ifp = ifp;
 	pktg->pktg_src = conf->pc_src;
 	pktg->pktg_ndst = conf->pc_ndst;
@@ -354,8 +365,8 @@ pktgen_start(struct pktgen *pktg)
 	if (cpuid != orig_cpuid)
 		lwkt_migratecpu(cpuid);
 
-	alloc_cnt = ifp->if_snd.ifq_maxlen * 2;
-	keep_cnt = (ifp->if_snd.ifq_maxlen * 3) / 4;
+	keep_cnt = pktg->pktg_pktenq;
+	alloc_cnt = keep_cnt * 2;
 
 	/*
 	 * Prefault enough mbuf into mbuf objcache
diff --git a/tools/tools/netrate/pktgen/pktgen.h b/tools/tools/netrate/pktgen/pktgen.h
index 3106a2b657f3..b07ae2cb1fd9 100644
--- a/tools/tools/netrate/pktgen/pktgen.h
+++ b/tools/tools/netrate/pktgen/pktgen.h
@@ -46,6 +46,7 @@ struct pktgen_conf {
 	struct sockaddr_in	pc_src;
 	int			pc_ndst;
 	struct sockaddr_in	*pc_dst;
+	int			pc_pktenq;
 };
 
 #define PKTGENSTART	_IO('G', 19)
diff --git a/tools/tools/netrate/pktgenctl/pktgenctl.c b/tools/tools/netrate/pktgenctl/pktgenctl.c
index 7db371591371..ef46b8a306b8 100644
--- a/tools/tools/netrate/pktgenctl/pktgenctl.c
+++ b/tools/tools/netrate/pktgenctl/pktgenctl.c
@@ -60,8 +60,6 @@
 #define INSRC_MASK	0x0002
 #define EADDR_MASK	0x0004
 #define IFACE_MASK	0x0008
-#define DATALEN_MASK	0x0010
-#define DURATION_MASK	0x0020
 
 #define MASK_NEEDED	(INDST_MASK | INSRC_MASK | EADDR_MASK | IFACE_MASK)
 
@@ -72,7 +70,7 @@ usage(void)
 	    "-d dst_inaddr[:dst_port] [-d dst_inaddr[:dst_port] ...] "
 	    "-s src_inaddr[:src_port] "
 	    "-e (gw_eaddr|dst_eaddr) -i iface "
-	    "[-m data_len] [-l duration] [-D dev]\n");
+	    "[-m data_len] [-l duration] [-D dev] [-q pktenq]\n");
 	exit(1);
 }
 
@@ -123,7 +121,7 @@ main(int argc, char *argv[])
 		err(1, "calloc(%d dst)", ndst_alloc);
 
 	conf.pc_ndst = 0;
-	while ((c = getopt(argc, argv, "d:s:e:i:m:l:D:")) != -1) {
+	while ((c = getopt(argc, argv, "d:s:e:i:m:l:D:q:")) != -1) {
 		switch (c) {
 		case 'd':
 			if (conf.pc_ndst >= ndst_alloc) {
@@ -182,18 +180,20 @@ main(int argc, char *argv[])
 
 		case 'm':
 			conf.pc_datalen = atoi(optarg);
-			arg_mask |= DATALEN_MASK;
 			break;
 
 		case 'l':
 			conf.pc_duration = atoi(optarg);
-			arg_mask |= DURATION_MASK;
 			break;
 
 		case 'D':
 			dev = optarg;
 			break;
 
+		case 'q':
+			conf.pc_pktenq = atoi(optarg);
+			break;
+
 		default:
 			usage();
 		}