diff --git a/sys/dev/rtwn/if_rtwn.c b/sys/dev/rtwn/if_rtwn.c
--- a/sys/dev/rtwn/if_rtwn.c
+++ b/sys/dev/rtwn/if_rtwn.c
@@ -247,6 +247,7 @@
 	    | IEEE80211_HTCAP_SMPS_OFF		/* SM PS mode disabled */
 	    /* s/w capabilities */
 	    | IEEE80211_HTC_HT			/* HT operation */
+	    | IEEE80211_HTC_RX_AMSDU_AMPDU	/* A-MSDU in A-MPDU */
 	    | IEEE80211_HTC_AMPDU		/* A-MPDU tx */
 	    | IEEE80211_HTC_AMSDU		/* A-MSDU tx */
 	    ;