diff --git a/monitor/msft.c b/monitor/msft.c
index fcbd057..46e7654 100644
--- a/monitor/msft.c
+++ b/monitor/msft.c
@@ -54,6 +54,8 @@ static void read_supported_features_rsp(const void *data, uint16_t size)
 	packet_print_features_msft(data);
 	print_field("Event prefix length: %u", evt_prefix_len);
 	packet_hexdump(data + 9, size - 9);
+
+	packet_set_msft_evt_prefix(data + 9, evt_prefix_len);
 }
 
 static void le_monitor_advertisement_cmd(const void *data, uint16_t size)
diff --git a/monitor/packet.c b/monitor/packet.c
index 9e849ac..fce2b76 100644
--- a/monitor/packet.c
+++ b/monitor/packet.c
@@ -266,6 +266,8 @@ struct index_data {
 	uint8_t  bdaddr[6];
 	uint16_t manufacturer;
 	uint16_t msft_opcode;
+	uint8_t  msft_evt_prefix[8];
+	uint8_t  msft_evt_len;
 	size_t   frame;
 };
 
@@ -281,6 +283,12 @@ void packet_set_fallback_manufacturer(uint16_t manufacturer)
 	fallback_manufacturer = manufacturer;
 }
 
+void packet_set_msft_evt_prefix(const uint8_t *prefix, uint8_t len)
+{
+	if (index_current < MAX_INDEX && len < 8)
+		memcpy(index_list[index_current].msft_evt_prefix, prefix, len);
+}
+
 static void print_packet(struct timeval *tv, struct ucred *cred, char ident,
 					uint16_t index, const char *channel,
 					const char *color, const char *label,
diff --git a/monitor/packet.h b/monitor/packet.h
index 34f988e..8a11bc7 100644
--- a/monitor/packet.h
+++ b/monitor/packet.h
@@ -31,6 +31,7 @@ void packet_del_filter(unsigned long filter);
 void packet_set_priority(const char *priority);
 void packet_select_index(uint16_t index);
 void packet_set_fallback_manufacturer(uint16_t manufacturer);
+void packet_set_msft_evt_prefix(const uint8_t *prefix, uint8_t len);
 
 void packet_hexdump(const unsigned char *buf, uint16_t len);
 void packet_print_error(const char *label, uint8_t error);