diff --git a/src/topo_node_sqlite.c b/src/topo_node_sqlite.c
index e5b51983..9a86f280 100644
--- a/src/topo_node_sqlite.c
+++ b/src/topo_node_sqlite.c
@@ -431,7 +431,8 @@ int topo_node_sqlite_channel_peers_all(sqlite3* db, const char* channel_id,
         }
         sqlite3_finalize(ast);
 
-        size_t peer_needed = 8 + 32 + 32 + 1 + 64 + 8 + 64 + 8 + 1 + (size_t)nl + 1;
+        uint8_t flags = (join_sig && join_ts) ? PEERS_FLAG_HAS_JOIN : 0;
+        size_t peer_needed = 8 + 32 + 32 + 1 + (flags & PEERS_FLAG_HAS_JOIN ? 64+8 : 0) + 64 + 8 + 1 + (size_t)nl + 1;
         size_t addr_sz = off - addr_start;
         if (addr_cnt > 0) {
             if (off + peer_needed > buf_sz) { sqlite3_finalize(stmt); return -2; }
@@ -444,7 +445,6 @@ int topo_node_sqlite_channel_peers_all(sqlite3* db, const char* channel_id,
         memcpy(buf + off, &node_id, 8); off += 8;
         memcpy(buf + off, x25519, 32); off += 32;
         memcpy(buf + off, ed_pub, 32); off += 32;
-        uint8_t flags = (join_sig && join_ts) ? PEERS_FLAG_HAS_JOIN : 0;
         buf[off++] = flags;
         if (flags & PEERS_FLAG_HAS_JOIN) {
             memcpy(buf + off, join_sig, 64); off += 64;
diff --git a/tools/chatgui/transport/chat_sync.c b/tools/chatgui/transport/chat_sync.c
index 130bb360..546912af 100644
--- a/tools/chatgui/transport/chat_sync.c
+++ b/tools/chatgui/transport/chat_sync.c
@@ -1258,36 +1258,48 @@ static void cs_handle_welcome(struct chat_sync* cs, uint64_t peer,
     uint16_t pc; memcpy(&pc, p, 2); p += 2;
     DEBUG_TRACE(DEBUG_CATEGORY_DB_SYNC, "%s: WELCOME ch=%s from=%016llx peers=%u", CS_ID, ch_id, (unsigned long long)peer, pc);
     for (uint16_t i = 0; i < pc; i++) {
-        if ((size_t)(p - pl) + 8 + 32 + 32 + 64 + 8 + 1 + 1 > len) break;
+        if ((size_t)(p - pl) + 8 + 32 + 32 + 1 + 64 + 8 + 1 > len) break;  /* min: id+x25519+ed+flags+update_sig(64+8)+nl+ac */
         uint64_t node_id; memcpy(&node_id, p, 8); p += 8;
         const uint8_t* x25519 = p; p += 32;
         const uint8_t* ed_pub = p; p += 32;
-        const uint8_t* join_sig = p; p += 64;
-        uint64_t join_ts; memcpy(&join_ts, p, 8); p += 8;
+        uint8_t flags = *p++;
+        const uint8_t* join_sig = NULL; uint64_t join_ts = 0;
+        if (flags & PEERS_FLAG_HAS_JOIN) {
+            if (p + 64 + 8 > pl + len) break;
+            join_sig = p; p += 64;
+            memcpy(&join_ts, p, 8); p += 8;
+        }
+        const uint8_t* update_sig = p; p += 64;
+        uint64_t update_ts; memcpy(&update_ts, p, 8); p += 8;
+        (void)update_sig; (void)update_ts;
         uint8_t nl = *p++;
         char peer_name[256] = "";
         if (nl && p + nl <= pl + len) { memcpy(peer_name, p, nl); peer_name[nl] = '\0'; p += nl; }
         uint8_t ac = *p++;
 
-        /* verify join_sig — all fields present in WELCOME wire */
-        uint8_t vmsg[256]; size_t vlen = 0;
-        vlen += snprintf((char*)vmsg + vlen, sizeof(vmsg) - vlen, "%s", ch_id) + 1;
-        memcpy(vmsg + vlen, &node_id, 8); vlen += 8;
-        memcpy(vmsg + vlen, x25519, 32); vlen += 32;
-        { const char* nm = peer_name[0] ? peer_name : "";
-          size_t nls = strlen(nm); memcpy(vmsg + vlen, nm, nls); vlen += nls; vmsg[vlen++] = '\0'; }
-        memcpy(vmsg + vlen, &join_ts, 8); vlen += 8;
-        { EVP_PKEY* pkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_ED25519, NULL, ed_pub, 32);
-          if (pkey) {
-            EVP_MD_CTX* ver = EVP_MD_CTX_new();
-            if (ver) {
-              if (EVP_DigestVerifyInit(ver, NULL, NULL, NULL, pkey) != 1
-                  || EVP_DigestVerify(ver, join_sig, 64, vmsg, vlen) != 1)
-                DEBUG_ERROR(DEBUG_CATEGORY_DB_SYNC, "%s: WELCOME invalid join_sig node=0x%016llx", CS_ID, (unsigned long long)node_id);
-              EVP_MD_CTX_free(ver);
+        /* verify join_sig if present */
+        if (join_sig) {
+            uint8_t vmsg[256]; size_t vlen = 0;
+            vlen += snprintf((char*)vmsg + vlen, sizeof(vmsg) - vlen, "%s", ch_id) + 1;
+            memcpy(vmsg + vlen, &node_id, 8); vlen += 8;
+            memcpy(vmsg + vlen, x25519, 32); vlen += 32;
+            { const char* nm = peer_name[0] ? peer_name : "";
+              size_t nls = strlen(nm); memcpy(vmsg + vlen, nm, nls); vlen += nls; vmsg[vlen++] = '\0'; }
+            memcpy(vmsg + vlen, &join_ts, 8); vlen += 8;
+            EVP_PKEY* pkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_ED25519, NULL, ed_pub, 32);
+            if (pkey) {
+                EVP_MD_CTX* ver = EVP_MD_CTX_new();
+                if (ver) {
+                    if (EVP_DigestVerifyInit(ver, NULL, NULL, NULL, pkey) != 1
+                        || EVP_DigestVerify(ver, join_sig, 64, vmsg, vlen) != 1) {
+                        DEBUG_ERROR(DEBUG_CATEGORY_DB_SYNC, "%s: WELCOME invalid join_sig node=0x%016llx — skipping", CS_ID, (unsigned long long)node_id);
+                        EVP_MD_CTX_free(ver); EVP_PKEY_free(pkey);
+                        continue;
+                    }
+                    EVP_MD_CTX_free(ver);
+                }
+                EVP_PKEY_free(pkey);
             }
-            EVP_PKEY_free(pkey);
-          }
         }
 
         int rc = topo_node_sqlite_member_put(db, ch_id, node_id, join_sig, join_ts, NULL, 0, x25519, ed_pub, peer_name, NULL);
@@ -1323,8 +1335,8 @@ static void cs_handle_welcome(struct chat_sync* cs, uint64_t peer,
                 DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "%s: [ADDR_SYNC] WELCOME INSERT v6 node=0x%016llx sock=%d port=%d",
                            CS_ID, (unsigned long long)node_id, sid, port);
         }
-        member_sync_cancel(g_cs->inst, peer, ch_id);
-        member_sync_set_online(g_cs->inst, peer, 0);
+        member_sync_cancel(g_cs->inst, node_id, ch_id);
+        member_sync_set_online(g_cs->inst, node_id, 0);
     }
 
     cs_refresh_channels(cs);