diff --git a/src/db_sync.c b/src/db_sync.c
index f261d1f3..52ebf521 100644
--- a/src/db_sync.c
+++ b/src/db_sync.c
@@ -1011,6 +1011,16 @@ static void db_handle_send_data(struct DB_SYNC_INSTANCE* si, uint64_t src, const
 
     db_cascade_from(si, fix_from);
 
+    for (int j = 0; j < si->peer_count; j++) {
+        if (si->peers[j].synced_pos >= fix_from && &si->peers[j] != sp) {
+            uint32_t old = si->peers[j].synced_pos;
+            si->peers[j].synced_pos = fix_from > 0 ? fix_from - 1 : 0;
+            DEBUG_DEBUG(DEBUG_CATEGORY_DB_SYNC, "sync [%s:%04llX] cascade changed chain from pos=%u → peer=%016llx synced_pos %u→%u",
+                        SI_SHRT(si), (unsigned long long)(src >> 16), fix_from,
+                        (unsigned long long)si->peers[j].node_id, old, si->peers[j].synced_pos);
+        }
+    }
+
     if (sp && received > 0) sp->synced_pos = from + received - 1;
 
     uint32_t mc = db_count(si);