diff --git a/mt7603/main.c b/mt7603/main.c
index 10c45503..43891912 100644
--- a/mt7603/main.c
+++ b/mt7603/main.c
@@ -318,8 +318,18 @@ mt7603_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 	}
 
 	if (changed & BSS_CHANGED_ERP_SLOT) {
+		u32 val;
+
 		dev->slottime = info->use_short_slot ? 9 : 20;
 		mt7603_mac_set_timing(dev);
+
+		if (info->use_short_slot)
+			val = MT7603_CFEND_RATE_DEFAULT;
+		else
+			val = MT7603_CFEND_RATE_11B;
+
+		mt76_rmw_field(dev, MT_AGG_CONTROL, MT_AGG_CONTROL_CFEND_RATE,
+			       val);
 	}
 
 	if (changed & (BSS_CHANGED_BEACON_ENABLED | BSS_CHANGED_BEACON_INT)) {
diff --git a/mt7603/mt7603.h b/mt7603/mt7603.h
index d19d6783..0e68d7f2 100644
--- a/mt7603/mt7603.h
+++ b/mt7603/mt7603.h
@@ -48,6 +48,9 @@
 
 #define MT7603_EDCCA_BLOCK_TH	10
 
+#define MT7603_CFEND_RATE_DEFAULT	0x69 /* chip default (24M) */
+#define MT7603_CFEND_RATE_11B		0x03 /* 11B LP, 11M */
+
 struct mt7603_vif;
 struct mt7603_sta;