diff --git a/mt7996/mcu.h b/mt7996/mcu.h
index 39a209f2..4e7842cd 100644
--- a/mt7996/mcu.h
+++ b/mt7996/mcu.h
@@ -950,7 +950,7 @@ enum {
 #define MT7996_BEACON_UPDATE_SIZE	(sizeof(struct bss_req_hdr) +		\
 					 sizeof(struct bss_bcn_content_tlv) +	\
 					 4 + MT_TXD_SIZE +			\
-					 sizeof(struct bss_bcn_cntdwn_tlv) +	\
+					 sizeof(struct bss_bcn_cntdwn_tlv) * 2 +	\
 					 sizeof(struct bss_bcn_mbss_tlv))
 #define MT7996_MAX_BSS_OFFLOAD_SIZE	2048
 #define MT7996_MAX_BEACON_SIZE		(MT7996_MAX_BSS_OFFLOAD_SIZE - \