diff --git a/src/entity/trx_maintenance_groups.ts b/src/entity/trx_maintenance_groups.ts
index 806da41..544d17f 100644
--- a/src/entity/trx_maintenance_groups.ts
+++ b/src/entity/trx_maintenance_groups.ts
@@ -8,9 +8,8 @@ export class TrxMaintenanceGroup {
 	@PrimaryGeneratedColumn("uuid")
 	id: string;
 
-	@ManyToOne(() => TrxMaintenance, { onDelete: "RESTRICT" })
-	@JoinTable()
-	maintenance: TrxMaintenance;
+	@OneToMany(() => TrxMaintenance, (mg) => mg.maintenance_group)
+	maintenance: TrxMaintenance[];
 
 	@Column({
 		nullable: true,
diff --git a/src/entity/trx_maintenances.ts b/src/entity/trx_maintenances.ts
index dd83d4b..e7da483 100644
--- a/src/entity/trx_maintenances.ts
+++ b/src/entity/trx_maintenances.ts
@@ -15,8 +15,9 @@ export class TrxMaintenance {
 	})
 	code: string;
 
-	@OneToMany(() => TrxMaintenanceGroup, (mg) => mg.maintenance)
-	maintenance_groups: TrxMaintenanceGroup[];
+	@ManyToOne(() => TrxMaintenanceGroup, { onDelete: "NO ACTION" })
+	@JoinTable()
+	maintenance_group: TrxMaintenanceGroup;
 
 	@ManyToOne(() => TrxCustomer, { onDelete: "RESTRICT" })
 	@JoinTable()