diff --git a/sys/dev/rtwn/pci/rtwn_pci_rx.c b/sys/dev/rtwn/pci/rtwn_pci_rx.c
--- a/sys/dev/rtwn/pci/rtwn_pci_rx.c
+++ b/sys/dev/rtwn/pci/rtwn_pci_rx.c
@@ -162,6 +162,8 @@
 	/* Send the frame to the 802.11 layer. */
 	RTWN_UNLOCK(sc);
 	if (ni != NULL) {
+		if (ni->ni_flags & IEEE80211_NODE_HT)
+			m->m_flags |= M_AMPDU;
 		(void)ieee80211_input_mimo(ni, m);
 		/* Node is no longer needed. */
 		ieee80211_free_node(ni);
diff --git a/sys/dev/rtwn/usb/rtwn_usb_rx.c b/sys/dev/rtwn/usb/rtwn_usb_rx.c
--- a/sys/dev/rtwn/usb/rtwn_usb_rx.c
+++ b/sys/dev/rtwn/usb/rtwn_usb_rx.c
@@ -412,6 +412,8 @@
 			ni = m->m_pkthdr.PH_loc.ptr;
 			m->m_pkthdr.PH_loc.ptr = NULL;
 			if (ni != NULL) {
+				if (ni->ni_flags & IEEE80211_NODE_HT)
+					m->m_flags |= M_AMPDU;
 				(void)ieee80211_input_mimo(ni, m);
 				ieee80211_free_node(ni);
 			} else {