diff --git a/httpd/page_impl.c b/httpd/page_impl.c
index bef34d9..ac389e8 100644
--- a/httpd/page_impl.c
+++ b/httpd/page_impl.c
@@ -637,7 +637,7 @@ void send_stp(void)
 		itoa_html(stp_pp2p[pi_i]);
 		/* designated info: a freshly heard BPDU wins, else we are the
 		 * segment's designated bridge and report our own values */
-		stp_we_root = stp_dbridge[pi_i].mac[5] && stp_bpdu_age[pi_i] < (uint16_t)stp_maxage_s * STP_HZ;
+		stp_we_root = stp_dpid[pi_i] && stp_bpdu_age[pi_i] < (uint16_t)stp_maxage_s * STP_HZ;
 		slen += strtox(outbuf + slen, ",\"db\":\"");
 		if (stp_we_root) {
 			pi_prio = stp_dbridge[pi_i].prio; pi_ext = stp_dbridge[pi_i].ext;
diff --git a/rtl837x_stp.c b/rtl837x_stp.c
index 6ad56e5..a0387e4 100644
--- a/rtl837x_stp.c
+++ b/rtl837x_stp.c
@@ -451,6 +451,16 @@ void stp_in(void) __banked
 		return;
 	}
 
+	stp_dbridge[port].prio = STP_I->bridge.prio;
+	stp_dbridge[port].ext = STP_I->bridge.ext;
+	memcpy(stp_dbridge[port].mac, STP_I->bridge.mac, 6);
+	stp_dpid[port] = ((uint16_t)STP_I->port_prio << 8) | STP_I->port_id;
+	stp_cost_scratch = STP_I->root_path_cost;
+	stp_dcost[port] = ((stp_cost_scratch & 0xff) << 24)
+			| ((stp_cost_scratch & 0xff00) << 8)
+			| ((stp_cost_scratch >> 8) & 0xff00)
+			| (stp_cost_scratch >> 24);
+
 	/* Better root than the one we know? */
 	if (STP_I->root.prio < root_bridge.prio
 		|| ((STP_I->root.prio == root_bridge.prio) && cmpMAC(STP_I->root.mac, root_bridge.mac) < 0)) {
@@ -480,13 +490,7 @@ void stp_in(void) __banked
 		/* Age of the information we now hold (see the TX note on the wire
 		 * format); saturate rather than wrap on absurd input. */
 		stp_msg_age = (STP_I->age > 254) ? 254 : (uint8_t)STP_I->age;
-		stp_cost_scratch = STP_I->root_path_cost;
-		/* big-endian on the wire */
-		root_bridge_cost = ((stp_cost_scratch & 0xff) << 24)
-		                 | ((stp_cost_scratch & 0xff00) << 8)
-		                 | ((stp_cost_scratch >> 8) & 0xff00)
-		                 | (stp_cost_scratch >> 24);
-		root_bridge_cost += PCOST(port);
+		root_bridge_cost = stp_dcost[port] + PCOST(port);
 	}
 	}
 }