diff --git a/src/entity/trx_maintenance_groups.ts b/src/entity/trx_maintenance_groups.ts
index b7e9c81..426d3b1 100644
--- a/src/entity/trx_maintenance_groups.ts
+++ b/src/entity/trx_maintenance_groups.ts
@@ -1,6 +1,7 @@
 import { Column, CreateDateColumn, DeleteDateColumn, Entity, JoinColumn, JoinTable, ManyToOne, OneToMany, PrimaryGeneratedColumn, UpdateDateColumn } from "typeorm";
 import { TrxMaintenancePosition, TrxMaintenanceStatus } from "../types/trx";
 import { TrxMaintenance } from "./trx_maintenances";
+import { TrxCustomer } from "./trx_customers";
 import { Status } from "../types/status";
 import { TrxMaintenanceGroupStatus } from "../types/trx";
 
@@ -9,6 +10,9 @@ export class TrxMaintenanceGroup {
 	@PrimaryGeneratedColumn("uuid")
 	id: string;
 
+	@OneToMany(() => TrxCustomer, (customer) => customer.id)
+	customer: TrxCustomer[];
+
 	@Column({
 		nullable: false,
 		length: 256,
diff --git a/src/entity/trx_maintenances.ts b/src/entity/trx_maintenances.ts
index 7ae3a1b..af7bfbc 100644
--- a/src/entity/trx_maintenances.ts
+++ b/src/entity/trx_maintenances.ts
@@ -19,6 +19,10 @@ export class TrxMaintenance {
 	@JoinTable()
 	maintenance_group: TrxMaintenanceGroup;
 
+	@ManyToOne(() => TrxCustomer, { onDelete: "NO ACTION" })
+	@JoinTable()
+	customer: TrxCustomer;
+
 	@Column({
 		nullable: false,
 		length: 64,