diff --git a/tests/test_main.py b/tests/test_main.py
index 9172337..1a7a420 100755
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -457,11 +457,13 @@ class StudentDefaultScoreScalar(Model):
     def test_column_default_callable(self):
         student_form = model_form(self.StudentDefaultScoreCallable, self.sess)()
         self.assertEqual(student_form._fields["score"].default, 5)
+        assert not contains_validator(student_form.score, InputRequired)
 
     def test_column_default_scalar(self):
         student_form = model_form(self.StudentDefaultScoreScalar, self.sess)()
         assert not isinstance(student_form._fields["score"].default, ColumnDefault)
         self.assertEqual(student_form._fields["score"].default, 10)
+        assert not contains_validator(student_form.score, InputRequired)
 
 
 class ModelFormTest2(TestCase):
diff --git a/wtforms_sqlalchemy/orm.py b/wtforms_sqlalchemy/orm.py
index e5c3a51..d1933d8 100644
--- a/wtforms_sqlalchemy/orm.py
+++ b/wtforms_sqlalchemy/orm.py
@@ -120,7 +120,7 @@ def convert(self, model, mapper, prop, field_args, db_session=None):
 
             kwargs["default"] = default
 
-            if column.nullable:
+            if column.nullable or default is not None:
                 kwargs["validators"].append(validators.Optional())
             else:
                 kwargs["validators"].append(validators.InputRequired())