diff --git a/infra/schema.sql b/infra/schema.sql
index a37dcc8..c4be426 100644
--- a/infra/schema.sql
+++ b/infra/schema.sql
@@ -24,12 +24,6 @@ ALTER TABLE cities ADD COLUMN IF NOT EXISTS resolution_m INTEGER NOT NULL DEFAUL
 ALTER TABLE cities ADD COLUMN IF NOT EXISTS boundary geometry(MultiPolygon, 4326);
 ALTER TABLE cities ADD COLUMN IF NOT EXISTS refresh_iter SMALLINT NOT NULL DEFAULT 0;
 
--- Migration: rename 'fifteen' mode to 'cyclist' and update CHECK constraint
-UPDATE grid_scores SET travel_mode = 'cyclist' WHERE travel_mode = 'fifteen';
-ALTER TABLE grid_scores DROP CONSTRAINT IF EXISTS grid_scores_travel_mode_check;
-ALTER TABLE grid_scores ADD CONSTRAINT grid_scores_travel_mode_check
-  CHECK (travel_mode IN ('walking','cycling','driving','transit','cyclist','cycling_walk','transit_walk'));
-
 CREATE INDEX IF NOT EXISTS idx_cities_bbox ON cities USING GIST (bbox);
 CREATE INDEX IF NOT EXISTS idx_cities_boundary ON cities USING GIST (boundary);
 
@@ -101,6 +95,16 @@ ALTER TABLE grid_scores ADD COLUMN IF NOT EXISTS profile TEXT NOT NULL DEFAULT '
 CREATE INDEX IF NOT EXISTS idx_grid_scores_lookup
   ON grid_scores (grid_point_id, travel_mode, threshold_min, profile);
 
+-- Migration: rename 'fifteen' mode to 'cyclist' and update CHECK constraint
+DO $$ BEGIN
+  IF EXISTS (SELECT FROM information_schema.tables WHERE table_name = 'grid_scores') THEN
+    UPDATE grid_scores SET travel_mode = 'cyclist' WHERE travel_mode = 'fifteen';
+  END IF;
+END $$;
+ALTER TABLE grid_scores DROP CONSTRAINT IF EXISTS grid_scores_travel_mode_check;
+ALTER TABLE grid_scores ADD CONSTRAINT grid_scores_travel_mode_check
+  CHECK (travel_mode IN ('walking','cycling','driving','transit','cyclist','cycling_walk','transit_walk'));
+
 -- ─── Nearest POIs per subcategory per grid point ─────────────────────────────
 -- Populated by compute-routing / compute-transit jobs. Stores up to K nearest
 -- POIs per (grid_point, category, subcategory, travel_mode) so that the scoring