diff --git a/migrations/0016_remove_legacy_features/up.sql b/migrations/0016_remove_legacy_features/up.sql
index 67c6f56..4270040 100644
--- a/migrations/0016_remove_legacy_features/up.sql
+++ b/migrations/0016_remove_legacy_features/up.sql
@@ -4,24 +4,187 @@ DROP TABLE IF EXISTS ticket_links;
 DROP TABLE IF EXISTS tickets;
 DROP TABLE IF EXISTS lot_model_mappings;
 
-ALTER TABLE parts
-    DROP FOREIGN KEY fk_parts_lot,
-    DROP INDEX idx_parts_lot,
-    DROP COLUMN lot_id;
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.table_constraints
+      WHERE constraint_schema = DATABASE()
+        AND table_name = 'parts'
+        AND constraint_name = 'fk_parts_lot'
+    ),
+    'ALTER TABLE parts DROP FOREIGN KEY fk_parts_lot',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
 
-ALTER TABLE machines
-    DROP FOREIGN KEY fk_machines_customer,
-    DROP FOREIGN KEY fk_machines_location,
-    DROP INDEX idx_machines_customer,
-    DROP INDEX idx_machines_location,
-    DROP COLUMN customer_id,
-    DROP COLUMN location_id;
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.statistics
+      WHERE table_schema = DATABASE()
+        AND table_name = 'parts'
+        AND index_name = 'idx_parts_lot'
+    ),
+    'ALTER TABLE parts DROP INDEX idx_parts_lot',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
 
-ALTER TABLE projects
-    DROP FOREIGN KEY fk_projects_customer,
-    DROP INDEX idx_projects_customer,
-    DROP INDEX uniq_projects_customer_name,
-    DROP COLUMN customer_id;
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.columns
+      WHERE table_schema = DATABASE()
+        AND table_name = 'parts'
+        AND column_name = 'lot_id'
+    ),
+    'ALTER TABLE parts DROP COLUMN lot_id',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.table_constraints
+      WHERE constraint_schema = DATABASE()
+        AND table_name = 'machines'
+        AND constraint_name = 'fk_machines_customer'
+    ),
+    'ALTER TABLE machines DROP FOREIGN KEY fk_machines_customer',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.table_constraints
+      WHERE constraint_schema = DATABASE()
+        AND table_name = 'machines'
+        AND constraint_name = 'fk_machines_location'
+    ),
+    'ALTER TABLE machines DROP FOREIGN KEY fk_machines_location',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.statistics
+      WHERE table_schema = DATABASE()
+        AND table_name = 'machines'
+        AND index_name = 'idx_machines_customer'
+    ),
+    'ALTER TABLE machines DROP INDEX idx_machines_customer',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.statistics
+      WHERE table_schema = DATABASE()
+        AND table_name = 'machines'
+        AND index_name = 'idx_machines_location'
+    ),
+    'ALTER TABLE machines DROP INDEX idx_machines_location',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.columns
+      WHERE table_schema = DATABASE()
+        AND table_name = 'machines'
+        AND column_name = 'customer_id'
+    ),
+    'ALTER TABLE machines DROP COLUMN customer_id',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.columns
+      WHERE table_schema = DATABASE()
+        AND table_name = 'machines'
+        AND column_name = 'location_id'
+    ),
+    'ALTER TABLE machines DROP COLUMN location_id',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.table_constraints
+      WHERE constraint_schema = DATABASE()
+        AND table_name = 'projects'
+        AND constraint_name = 'fk_projects_customer'
+    ),
+    'ALTER TABLE projects DROP FOREIGN KEY fk_projects_customer',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.statistics
+      WHERE table_schema = DATABASE()
+        AND table_name = 'projects'
+        AND index_name = 'idx_projects_customer'
+    ),
+    'ALTER TABLE projects DROP INDEX idx_projects_customer',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.statistics
+      WHERE table_schema = DATABASE()
+        AND table_name = 'projects'
+        AND index_name = 'uniq_projects_customer_name'
+    ),
+    'ALTER TABLE projects DROP INDEX uniq_projects_customer_name',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(
+    EXISTS(
+      SELECT 1 FROM information_schema.columns
+      WHERE table_schema = DATABASE()
+        AND table_name = 'projects'
+        AND column_name = 'customer_id'
+    ),
+    'ALTER TABLE projects DROP COLUMN customer_id',
+    'SELECT 1'
+  )
+);
+PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;
 
 DROP TABLE IF EXISTS lots;
 DROP TABLE IF EXISTS locations;