diff --git a/db/migrations/014_known_routes_last_seen_index.sql b/db/migrations/014_known_routes_last_seen_index.sql
new file mode 100644
index 0000000..faa5808
--- /dev/null
+++ b/db/migrations/014_known_routes_last_seen_index.sql
@@ -0,0 +1,3 @@
+-- Routes list orders by last_seen; index it (was seq-scanning ~150k rows per page).
+
+CREATE INDEX idx_known_routes_last_seen ON known_routes(last_seen DESC);