diff --git a/associations/belongs_to_association.go b/associations/belongs_to_association.go
index 2d70667c..a28e5d0a 100644
--- a/associations/belongs_to_association.go
+++ b/associations/belongs_to_association.go
@@ -31,7 +31,23 @@ func belongsToAssociationBuilder(p associationParams) (Association, error) {
 	ownerVal := p.modelValue.FieldByName(p.field.Name)
 	tags := p.popTags
 	primaryIDField := defaults.String(tags.Find("primary_id").Value, "ID")
-	ownerIDField := defaults.String(tags.Find("fk_id").Value, fmt.Sprintf("%s%s", p.field.Name, "ID"))
+	ownerIDField := fmt.Sprintf("%s%s", p.field.Name, "ID")
+
+	if tags.Find("fk_id").Value != "" {
+		dbTag := tags.Find("fk_id").Value
+		if _, found := p.modelType.FieldByName(dbTag); !found {
+			t := p.modelValue.Type()
+			for i := 0; i < t.NumField(); i++ {
+				f := t.Field(i)
+				if f.Tag.Get("db") == dbTag {
+					ownerIDField = f.Name
+					break
+				}
+			}
+		} else {
+			ownerIDField = dbTag
+		}
+	}
 
 	// belongs_to requires an holding field for the foreign model ID.
 	if _, found := p.modelType.FieldByName(ownerIDField); !found {
diff --git a/executors_test.go b/executors_test.go
index 5af9304b..8b263c72 100644
--- a/executors_test.go
+++ b/executors_test.go
@@ -972,7 +972,7 @@ func Test_Eager_Create_Belongs_To(t *testing.T) {
 
 		car := Taxi{
 			Model: "Fancy car",
-			Driver: User{
+			Driver: &User{
 				Name: nulls.NewString("Larry 2"),
 			},
 		}
@@ -1101,7 +1101,7 @@ func Test_Flat_Create_Belongs_To(t *testing.T) {
 
 		car := Taxi{
 			Model:  "Fancy car",
-			Driver: user,
+			Driver: &user,
 		}
 
 		err = tx.Create(&car)
diff --git a/pop_test.go b/pop_test.go
index 6dd812af..20e4eda5 100644
--- a/pop_test.go
+++ b/pop_test.go
@@ -124,7 +124,7 @@ type Taxi struct {
 	ID        int       `db:"id"`
 	Model     string    `db:"model"`
 	UserID    nulls.Int `db:"user_id"`
-	Driver    User      `belongs_to:"user" fk_id:"UserID"`
+	Driver    *User     `belongs_to:"user" fk_id:"user_id"`
 	CreatedAt time.Time `db:"created_at"`
 	UpdatedAt time.Time `db:"updated_at"`
 }
diff --git a/preload_associations.go b/preload_associations.go
index e78039a2..5d3be99a 100644
--- a/preload_associations.go
+++ b/preload_associations.go
@@ -159,7 +159,8 @@ func (ami *AssociationMetaInfo) fkName() string {
 		t = reflectx.Deref(t.Elem())
 	}
 	fkName := fmt.Sprintf("%s%s", flect.Underscore(flect.Singularize(t.Name())), "_id")
-	return defaults.String(ami.Field.Tag.Get("fk_id"), fkName)
+	fkNameTag := flect.Underscore(ami.Field.Tag.Get("fk_id"))
+	return defaults.String(fkNameTag, fkName)
 }
 
 // preload is the query mode used to load associations from database
@@ -269,11 +270,15 @@ func preloadHasMany(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaInf
 			asocValue := slice.Elem().Index(i)
 			if mmi.mapper.FieldByName(mvalue, "ID").Interface() == mmi.mapper.FieldByName(asocValue, foreignField.Path).Interface() ||
 				reflect.DeepEqual(mmi.mapper.FieldByName(mvalue, "ID"), mmi.mapper.FieldByName(asocValue, foreignField.Path)) {
-				if modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array {
+
+				switch {
+				case modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array:
 					modelAssociationField.Set(reflect.Append(modelAssociationField, asocValue))
-					continue
+				case modelAssociationField.Kind() == reflect.Ptr:
+					modelAssociationField.Elem().Set(reflect.Append(modelAssociationField.Elem(), asocValue))
+				default:
+					modelAssociationField.Set(asocValue)
 				}
-				modelAssociationField.Set(asocValue)
 			}
 		}
 	})
@@ -339,6 +344,10 @@ func preloadHasOne(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaInfo
 func preloadBelongsTo(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaInfo) error {
 	// 1) get all associations ids.
 	fi := mmi.getDBFieldTaggedWith(asoc.fkName())
+	if fi == nil {
+		fi = mmi.getDBFieldTaggedWith(fmt.Sprintf("%s%s", flect.Underscore(asoc.Path), "_id"))
+	}
+
 	fkids := []interface{}{}
 	mmi.iterate(func(val reflect.Value) {
 		fkids = append(fkids, mmi.mapper.FieldByName(val, fi.Path).Interface())
@@ -375,11 +384,15 @@ func preloadBelongsTo(tx *Connection, asoc *AssociationMetaInfo, mmi *ModelMetaI
 			asocValue := slice.Elem().Index(i)
 			if mmi.mapper.FieldByName(mvalue, fi.Path).Interface() == mmi.mapper.FieldByName(asocValue, "ID").Interface() ||
 				reflect.DeepEqual(mmi.mapper.FieldByName(mvalue, fi.Path), mmi.mapper.FieldByName(asocValue, "ID")) {
-				if modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array {
+
+				switch {
+				case modelAssociationField.Kind() == reflect.Slice || modelAssociationField.Kind() == reflect.Array:
 					modelAssociationField.Set(reflect.Append(modelAssociationField, asocValue))
-					continue
+				case modelAssociationField.Kind() == reflect.Ptr:
+					modelAssociationField.Elem().Set(asocValue)
+				default:
+					modelAssociationField.Set(asocValue)
 				}
-				modelAssociationField.Set(asocValue)
 			}
 		}
 	})
diff --git a/preload_associations_test.go b/preload_associations_test.go
index ed4f7ae0..a7fe4a59 100644
--- a/preload_associations_test.go
+++ b/preload_associations_test.go
@@ -182,3 +182,24 @@ func Test_New_Implementation_For_Nplus1_Nested(t *testing.T) {
 		SetEagerMode(EagerDefault)
 	})
 }
+
+func Test_New_Implementation_For_Nplus1_BelongsTo_Not_Underscore(t *testing.T) {
+	if PDB == nil {
+		t.Skip("skipping integration tests")
+	}
+	transaction(func(tx *Connection) {
+		a := require.New(t)
+		user := User{Name: nulls.NewString("Mark")}
+		a.NoError(tx.Create(&user))
+
+		taxi := Taxi{UserID: nulls.NewInt(user.ID)}
+		a.NoError(tx.Create(&taxi))
+
+		SetEagerMode(EagerPreload)
+		taxis := []Taxi{}
+		a.NoError(tx.EagerPreload().All(&taxis))
+		a.Len(taxis, 1)
+		a.Equal("Mark", taxis[0].Driver.Name.String)
+		SetEagerMode(EagerDefault)
+	})
+}
diff --git a/soda/cmd/version.go b/soda/cmd/version.go
index 119bcf37..3e207cb3 100644
--- a/soda/cmd/version.go
+++ b/soda/cmd/version.go
@@ -1,4 +1,4 @@
 package cmd
 
 // Version defines the current Pop version.
-const Version = "v5.1.1"
+const Version = "v5.1.2"