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
@@ -1308,12 +1308,14 @@
 		ieee80211_free_node(ni);
 	}
 
-
-	if (basicrates == 0)
+	if (basicrates == 0) {
+		device_printf(sc->sc_dev,
+		    "WARNING: no configured basic rates!\n");
 		return;
+	}
 
-	/* XXX also set initial RTS rate? */
 	rtwn_set_basicrates(sc, basicrates);
+	rtwn_set_rts_rate(sc, basicrates);
 }
 
 static int
diff --git a/sys/dev/rtwn/if_rtwn_rx.h b/sys/dev/rtwn/if_rtwn_rx.h
--- a/sys/dev/rtwn/if_rtwn_rx.h
+++ b/sys/dev/rtwn/if_rtwn_rx.h
@@ -23,6 +23,7 @@
 	    const struct ieee80211_htrateset *, uint32_t *, uint32_t *,
 	    int *, int);
 void	rtwn_set_basicrates(struct rtwn_softc *, uint32_t);
+void	rtwn_set_rts_rate(struct rtwn_softc *, uint32_t);
 struct ieee80211_node *	rtwn_rx_common(struct rtwn_softc *, struct mbuf *,
 	    void *);
 void	rtwn_adhoc_recv_mgmt(struct ieee80211_node *, struct mbuf *, int,
diff --git a/sys/dev/rtwn/if_rtwn_rx.c b/sys/dev/rtwn/if_rtwn_rx.c
--- a/sys/dev/rtwn/if_rtwn_rx.c
+++ b/sys/dev/rtwn/if_rtwn_rx.c
@@ -134,6 +134,41 @@
 	rtwn_setbits_4(sc, R92C_RRSR, R92C_RRSR_RATE_BITMAP_M, rates);
 }
 
+/*
+ * Configure the initial RTS rate to use.
+ */
+void
+rtwn_set_rts_rate(struct rtwn_softc *sc, uint32_t rates)
+{
+	uint8_t ridx;
+
+	/*
+	 * We shouldn't set the initial RTS/CTS generation rate
+	 * as the highest available rate - that may end up
+	 * with trying to configure something like MCS1 RTS/CTS.
+	 *
+	 * Instead, choose a suitable low OFDM/CCK rate based
+	 * on the basic rate bitmask.  Assume the caller
+	 * has filtered out CCK modes in 5GHz.
+	 */
+	rates &= (1 << RTWN_RIDX_CCK1) | (1 << RTWN_RIDX_CCK55) |
+	    (1 << RTWN_RIDX_CCK11) | (1 << RTWN_RIDX_OFDM6) |
+	    (1 << RTWN_RIDX_OFDM9) | (1 << RTWN_RIDX_OFDM12) |
+	    (1 << RTWN_RIDX_OFDM18) | (1 << RTWN_RIDX_OFDM24);
+	if (rates == 0) {
+		device_printf(sc->sc_dev,
+		    "WARNING: no configured basic RTS rate!\n");
+		return;
+	}
+	ridx = fls(rates) - 1;
+
+	RTWN_DPRINTF(sc, RTWN_DEBUG_RA,
+	    "%s: mask=0x%08x, ridx=%d\n",
+	    __func__, rates, ridx);
+
+	rtwn_write_1(sc, R92C_INIRTS_RATE_SEL, ridx);
+}
+
 static void
 rtwn_update_avgrssi(struct rtwn_softc *sc, struct rtwn_node *un, int8_t rssi,
     int is_cck)