diff --git a/customize_column_test.go b/customize_column_test.go
index 29400cd0..93bab2e1 100644
--- a/customize_column_test.go
+++ b/customize_column_test.go
@@ -142,9 +142,17 @@ func TestOneToOneWithCustomizedColumn(t *testing.T) {
 
 type PromotionDiscount struct {
 	gorm.Model
-	Name    string
-	Coupons []*PromotionCoupon `gorm:"ForeignKey:discount_id"`
-	Rule    *PromotionRule     `gorm:"ForeignKey:discount_id"`
+	Name     string
+	Coupons  []*PromotionCoupon `gorm:"ForeignKey:discount_id"`
+	Rule     *PromotionRule     `gorm:"ForeignKey:discount_id"`
+	Benefits []PromotionBenefit `gorm:"ForeignKey:promotion_id"`
+}
+
+type PromotionBenefit struct {
+	gorm.Model
+	Name        string
+	PromotionID uint
+	Discount    PromotionDiscount `gorm:"ForeignKey:promotion_id"`
 }
 
 type PromotionCoupon struct {
@@ -198,7 +206,7 @@ func TestOneToManyWithCustomizedColumn(t *testing.T) {
 	}
 }
 
-func TestOneToOneWithPartialCustomizedColumn(t *testing.T) {
+func TestHasOneWithPartialCustomizedColumn(t *testing.T) {
 	DB.DropTable(&PromotionDiscount{}, &PromotionRule{})
 	DB.AutoMigrate(&PromotionDiscount{}, &PromotionRule{})
 
@@ -235,3 +243,38 @@ func TestOneToOneWithPartialCustomizedColumn(t *testing.T) {
 		t.Errorf("should preload discount from rule")
 	}
 }
+
+func TestBelongsToWithPartialCustomizedColumn(t *testing.T) {
+	DB.DropTable(&PromotionDiscount{}, &PromotionBenefit{})
+	DB.AutoMigrate(&PromotionDiscount{}, &PromotionBenefit{})
+
+	discount := PromotionDiscount{
+		Name: "Happy New Year 3",
+		Benefits: []PromotionBenefit{
+			{Name: "free cod"},
+			{Name: "free shipping"},
+		},
+	}
+
+	if err := DB.Create(&discount).Error; err != nil {
+		t.Errorf("no error should happen but got %v", err)
+	}
+
+	var discount1 PromotionDiscount
+	if err := DB.Preload("Benefits").First(&discount1, "id = ?", discount.ID).Error; err != nil {
+		t.Errorf("no error should happen but got %v", err)
+	}
+
+	if len(discount.Benefits) != 2 {
+		t.Errorf("should find two benefits")
+	}
+
+	var benefit PromotionBenefit
+	if err := DB.Preload("Discount").First(&benefit, "name = ?", "free cod").Error; err != nil {
+		t.Errorf("no error should happen but got %v", err)
+	}
+
+	if benefit.Discount.Name != "Happy New Year 3" {
+		t.Errorf("should preload discount from coupon")
+	}
+}