diff --git a/db/migration/000001_init_schema.up.sql b/db/migration/000001_init_schema.up.sql
index 44ca972..91e4cc2 100644
--- a/db/migration/000001_init_schema.up.sql
+++ b/db/migration/000001_init_schema.up.sql
@@ -35,7 +35,7 @@ CREATE TABLE "customers" (
 
 CREATE TABLE "persons" (
   "ID" bigserial UNIQUE PRIMARY KEY NOT NULL,
-  "customerID" bigserial,
+  "customerID" bigserial NOT NULL,
   "firstname" varchar NOT NULL,
   "lastname" varchar NOT NULL,
   "birthday" timestamptz NOT NULL,