diff --git a/dialect/dialect.go b/dialect/dialect.go
index 9418e533..a0f403c4 100644
--- a/dialect/dialect.go
+++ b/dialect/dialect.go
@@ -1,10 +1,17 @@
 package dialect
 
+import (
+	"reflect"
+	"time"
+)
+
+var timeType = reflect.TypeOf(time.Time{})
+
 type Dialect interface {
 	BinVar(i int) string
 	SupportLastInsertId() bool
-	SqlTag(column interface{}, size int) string
-	PrimaryKeyTag(column interface{}, size int) string
+	SqlTag(value reflect.Value, size int) string
+	PrimaryKeyTag(value reflect.Value, size int) string
 	ReturningStr(key string) string
 	Quote(key string) string
 }
diff --git a/dialect/mysql.go b/dialect/mysql.go
index 2a5ac0c0..9602bcc1 100644
--- a/dialect/mysql.go
+++ b/dialect/mysql.go
@@ -2,7 +2,7 @@ package dialect
 
 import (
 	"fmt"
-	"time"
+	"reflect"
 )
 
 type mysql struct{}
@@ -15,41 +15,44 @@ func (s *mysql) SupportLastInsertId() bool {
 	return true
 }
 
-func (d *mysql) SqlTag(column interface{}, size int) string {
-	switch column.(type) {
-	case time.Time:
-		return "datetime"
-	case bool:
+func (d *mysql) SqlTag(value reflect.Value, size int) string {
+	switch value.Kind() {
+	case reflect.Bool:
 		return "boolean"
-	case int, int8, int16, int32, uint, uint8, uint16, uint32:
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
 		return "int"
-	case int64, uint64:
+	case reflect.Int64, reflect.Uint64:
 		return "bigint"
-	case float32, float64:
+	case reflect.Float32, reflect.Float64:
 		return "double"
-	case []byte:
-		if size > 0 && size < 65532 {
-			return fmt.Sprintf("varbinary(%d)", size)
-		} else {
-			return "longblob"
-		}
-	case string:
+	case reflect.String:
 		if size > 0 && size < 65532 {
 			return fmt.Sprintf("varchar(%d)", size)
 		} else {
 			return "longtext"
 		}
+	case reflect.Struct:
+		if value.Type() == timeType {
+			return "datetime"
+		}
 	default:
-		panic("Invalid sql type for mysql")
+		if _, ok := value.Interface().([]byte); ok {
+			if size > 0 && size < 65532 {
+				return fmt.Sprintf("varbinary(%d)", size)
+			} else {
+				return "longblob"
+			}
+		}
 	}
+	panic(fmt.Sprintf("invalid sql type %s (%s) for mysql", value.Type().Name(), value.Kind().String()))
 }
 
-func (s *mysql) PrimaryKeyTag(column interface{}, size int) string {
+func (s *mysql) PrimaryKeyTag(value reflect.Value, size int) string {
 	suffix_str := " NOT NULL AUTO_INCREMENT PRIMARY KEY"
-	switch column.(type) {
-	case int, int8, int16, int32, uint, uint8, uint16, uint32:
+	switch value.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
 		return "int" + suffix_str
-	case int64, uint64:
+	case reflect.Int64, reflect.Uint64:
 		return "bigint" + suffix_str
 	default:
 		panic("Invalid primary key type")
diff --git a/dialect/postgres.go b/dialect/postgres.go
index 7cffe9dc..7b744fa4 100644
--- a/dialect/postgres.go
+++ b/dialect/postgres.go
@@ -2,7 +2,7 @@ package dialect
 
 import (
 	"fmt"
-	"time"
+	"reflect"
 )
 
 type postgres struct {
@@ -16,36 +16,38 @@ func (s *postgres) SupportLastInsertId() bool {
 	return false
 }
 
-func (d *postgres) SqlTag(column interface{}, size int) string {
-	switch column.(type) {
-	case time.Time:
-		return "timestamp with time zone"
-	case bool:
+func (d *postgres) SqlTag(value reflect.Value, size int) string {
+	switch value.Kind() {
+	case reflect.Bool:
 		return "boolean"
-	case int, int8, int16, int32, uint, uint8, uint16, uint32:
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
 		return "integer"
-	case int64, uint64:
+	case reflect.Int64, reflect.Uint64:
 		return "bigint"
-	case float32, float64:
+	case reflect.Float32, reflect.Float64:
 		return "numeric"
-	case []byte:
-		return "bytea"
-	case string:
+	case reflect.String:
 		if size > 0 && size < 65532 {
 			return fmt.Sprintf("varchar(%d)", size)
-		} else {
-			return "text"
+		}
+		return "text"
+	case reflect.Struct:
+		if value.Type() == timeType {
+			return "timestamp with time zone"
 		}
 	default:
-		panic("Invalid sql type for postgres")
+		if _, ok := value.Interface().([]byte); ok {
+			return "bytea"
+		}
 	}
+	panic(fmt.Sprintf("invalid sql type %s (%s) for postgres", value.Type().Name(), value.Kind().String()))
 }
 
-func (s *postgres) PrimaryKeyTag(column interface{}, size int) string {
-	switch column.(type) {
-	case int, int8, int16, int32, uint, uint8, uint16, uint32:
+func (s *postgres) PrimaryKeyTag(value reflect.Value, size int) string {
+	switch value.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
 		return "serial PRIMARY KEY"
-	case int64, uint64:
+	case reflect.Int64, reflect.Uint64:
 		return "bigserial PRIMARY KEY"
 	default:
 		panic("Invalid primary key type")
diff --git a/dialect/sqlite3.go b/dialect/sqlite3.go
index 4d16c3a8..ae54e603 100644
--- a/dialect/sqlite3.go
+++ b/dialect/sqlite3.go
@@ -2,7 +2,7 @@ package dialect
 
 import (
 	"fmt"
-	"time"
+	"reflect"
 )
 
 type sqlite3 struct{}
@@ -15,33 +15,41 @@ func (s *sqlite3) SupportLastInsertId() bool {
 	return true
 }
 
-func (s *sqlite3) SqlTag(column interface{}, size int) string {
-	switch column.(type) {
-	case time.Time:
-		return "datetime"
-	case bool:
+func (s *sqlite3) SqlTag(value reflect.Value, size int) string {
+	switch value.Kind() {
+	case reflect.Bool:
 		return "bool"
-	case int, int8, int16, int32, uint, uint8, uint16, uint32:
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr:
 		return "integer"
-	case int64, uint64:
+	case reflect.Int64, reflect.Uint64:
 		return "bigint"
-	case float32, float64:
+	case reflect.Float32, reflect.Float64:
 		return "real"
-	case []byte:
-		return "blob"
-	case string:
+	case reflect.String:
 		if size > 0 && size < 65532 {
 			return fmt.Sprintf("varchar(%d)", size)
 		} else {
 			return "text"
 		}
+	case reflect.Struct:
+		if value.Type() == timeType {
+			return "datetime"
+		}
 	default:
-		panic("Invalid sql type for sqlite3")
+		if _, ok := value.Interface().([]byte); ok {
+			return "blob"
+		}
 	}
+	panic(fmt.Sprintf("invalid sql type %s (%s) for sqlite3", value.Type().Name(), value.Kind().String()))
 }
 
-func (s *sqlite3) PrimaryKeyTag(column interface{}, size int) string {
-	return "INTEGER PRIMARY KEY"
+func (s *sqlite3) PrimaryKeyTag(value reflect.Value, size int) string {
+	switch value.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uintptr, reflect.Int64, reflect.Uint64:
+		return "INTEGER PRIMARY KEY"
+	default:
+		panic("Invalid primary key type")
+	}
 }
 
 func (s *sqlite3) ReturningStr(key string) (str string) {
diff --git a/main_test.go b/main_test.go
index 1df4558a..f244c03d 100644
--- a/main_test.go
+++ b/main_test.go
@@ -22,6 +22,17 @@ type IgnoredEmbedStruct struct {
 	Name string
 }
 
+type Num int64
+
+func (i *Num) Scan(src interface{}) error {
+	v := reflect.ValueOf(src)
+	if v.Kind() != reflect.Int64 {
+		return errors.New("Cannot scan NamedInt from " + v.String())
+	}
+	*i = Num(v.Int())
+	return nil
+}
+
 type User struct {
 	Id                 int64 // Id: Primary key
 	Age                int64
@@ -42,6 +53,7 @@ type User struct {
 	PasswordHash       []byte
 	IgnoreMe           int64    `sql:"-"`
 	IgnoreStringSlice  []string `sql:"-"`
+	UserNum            Num
 }
 
 type CreditCard struct {
@@ -156,7 +168,7 @@ func init() {
 	t3, _ = time.Parse(shortForm, "2005-01-01 00:00:00")
 	t4, _ = time.Parse(shortForm, "2010-01-01 00:00:00")
 	t5, _ = time.Parse(shortForm, "2020-01-01 00:00:00")
-	db.Save(&User{Name: "1", Age: 18, Birthday: t1, When: time.Now()})
+	db.Save(&User{Name: "1", Age: 18, Birthday: t1, When: time.Now(), UserNum: Num(111)})
 	db.Save(&User{Name: "2", Age: 20, Birthday: t2})
 	db.Save(&User{Name: "3", Age: 22, Birthday: t3})
 	db.Save(&User{Name: "3", Age: 24, Birthday: t4})
@@ -181,6 +193,22 @@ func TestFirstAndLast(t *testing.T) {
 	}
 }
 
+func TestSaveCustomType(t *testing.T) {
+	var user, user1 User
+	db.First(&user, "name = ?", "1")
+	if user.UserNum != Num(111) {
+		t.Errorf("UserNum should be saved correctly")
+	}
+
+	user.UserNum = Num(222)
+	db.Save(&user)
+
+	db.First(&user1, "name = ?", "1")
+	if user1.UserNum != Num(222) {
+		t.Errorf("UserNum should be updated correctly")
+	}
+}
+
 func TestPrecision(t *testing.T) {
 	f := 35.03554004971999
 	user := User{Name: "Precision", Latitude: f}
diff --git a/scope_private.go b/scope_private.go
index 7212af2b..c2e5627e 100644
--- a/scope_private.go
+++ b/scope_private.go
@@ -309,26 +309,24 @@ func (scope *Scope) sqlTagForField(field *Field) (tag string) {
 	value := field.Value
 	reflectValue := reflect.ValueOf(value)
 
-	if field.IsScanner() {
-		value = reflectValue.Field(0).Interface()
-	}
-
 	switch reflectValue.Kind() {
 	case reflect.Slice:
 		if _, ok := value.([]byte); !ok {
 			return
 		}
 	case reflect.Struct:
-		if !field.IsTime() && !field.IsScanner() {
+		if field.IsScanner() {
+			reflectValue = reflectValue.Field(0)
+		} else if !field.IsTime() {
 			return
 		}
 	}
 
 	if len(tag) == 0 {
 		if field.isPrimaryKey {
-			tag = scope.Dialect().PrimaryKeyTag(value, size)
+			tag = scope.Dialect().PrimaryKeyTag(reflectValue, size)
 		} else {
-			tag = scope.Dialect().SqlTag(value, size)
+			tag = scope.Dialect().SqlTag(reflectValue, size)
 		}
 	}