diff --git a/src/wuttasync/importing/base.py b/src/wuttasync/importing/base.py
index e8aa523..629ead6 100644
--- a/src/wuttasync/importing/base.py
+++ b/src/wuttasync/importing/base.py
@@ -29,6 +29,7 @@ import os
 import logging
 from collections import OrderedDict
 
+import sqlalchemy as sa
 from sqlalchemy import orm
 from sqlalchemy_utils.functions import get_primary_keys, get_columns
 
@@ -188,7 +189,10 @@ class Importer:  # pylint: disable=too-many-instance-attributes,too-many-public-
     max_delete = None
     max_total = None
 
-    def __init__(self, config, handler=None, model_class=None, **kwargs):
+    handler = None
+    model_class = None
+
+    def __init__(self, config, **kwargs):
         self.config = config
         self.app = self.config.get_app()
 
@@ -202,8 +206,6 @@ class Importer:  # pylint: disable=too-many-instance-attributes,too-many-public-
             "delete", kwargs.pop("allow_delete", self.allow_delete)
         )
 
-        self.handler = handler
-        self.model_class = model_class
         self.__dict__.update(kwargs)
 
         self.fields = self.get_fields()
@@ -272,7 +274,10 @@ class Importer:  # pylint: disable=too-many-instance-attributes,too-many-public-
         if hasattr(self, "simple_fields"):
             return self.simple_fields
 
-        fields = get_columns(self.model_class)
+        try:
+            fields = get_columns(self.model_class)
+        except sa.exc.NoInspectionAvailable:
+            return []
         return list(fields.keys())
 
     def get_supported_fields(self):
@@ -1008,9 +1013,7 @@ class Importer:  # pylint: disable=too-many-instance-attributes,too-many-public-
             return None
 
         obj = self.make_empty_object(key)
-        if obj:
-            return self.update_target_object(obj, source_data)
-        return None
+        return self.update_target_object(obj, source_data)
 
     def make_empty_object(self, key):
         """
@@ -1039,7 +1042,9 @@ class Importer:  # pylint: disable=too-many-instance-attributes,too-many-public-
 
         Default logic will make a new instance of :attr:`model_class`.
         """
-        return self.model_class()
+        if callable(self.model_class):
+            return self.model_class()  # pylint: disable=not-callable
+        raise AttributeError("model_class is not callable!")
 
     def update_target_object(self, obj, source_data, target_data=None):
         """
diff --git a/tests/importing/test_base.py b/tests/importing/test_base.py
index 2ec9164..08c37a2 100644
--- a/tests/importing/test_base.py
+++ b/tests/importing/test_base.py
@@ -406,11 +406,18 @@ class TestImporter(DataTestCase):
     def test_normalize_source_object_all(self):
         model = self.app.model
         imp = self.make_importer(model_class=model.Setting)
+
+        # normal
         setting = model.Setting()
         result = imp.normalize_source_object_all(setting)
         self.assertEqual(len(result), 1)
         self.assertIs(result[0], setting)
 
+        # unwanted (normalized is None)
+        with patch.object(imp, "normalize_source_object", return_value=None):
+            result = imp.normalize_source_object_all(setting)
+            self.assertIsNone(result)
+
     def test_normalize_source_object(self):
         model = self.app.model
         imp = self.make_importer(model_class=model.Setting)
@@ -532,10 +539,16 @@ class TestImporter(DataTestCase):
 
     def test_make_object(self):
         model = self.app.model
+
+        # normal
         imp = self.make_importer(model_class=model.Setting)
         obj = imp.make_object()
         self.assertIsInstance(obj, model.Setting)
 
+        # no model_class
+        imp = self.make_importer()
+        self.assertRaises(AttributeError, imp.make_object)
+
     def test_update_target_object(self):
         model = self.app.model
         imp = self.make_importer(model_class=model.Setting)
@@ -707,13 +720,20 @@ class TestToSqlalchemy(DataTestCase):
         imp = self.make_importer(model_class=model.Setting, target_session=self.session)
         setting = model.Setting(name="foo", value="bar")
 
-        # new object is added to session
+        # normal; new object is added to session
         setting = imp.create_target_object(("foo",), {"name": "foo", "value": "bar"})
         self.assertIsInstance(setting, model.Setting)
         self.assertEqual(setting.name, "foo")
         self.assertEqual(setting.value, "bar")
         self.assertIn(setting, self.session)
 
+        # unwanted; parent class does not create the object
+        with patch.object(mod.Importer, "create_target_object", return_value=None):
+            setting = imp.create_target_object(
+                ("foo",), {"name": "foo", "value": "bar"}
+            )
+            self.assertIsNone(setting)
+
     def test_delete_target_object(self):
         model = self.app.model
 
diff --git a/tests/importing/test_csv.py b/tests/importing/test_csv.py
index acd5f8e..8544d63 100644
--- a/tests/importing/test_csv.py
+++ b/tests/importing/test_csv.py
@@ -82,8 +82,8 @@ foo2,bar2
         imp.input_file_path = self.data_path
         imp.open_input_file()
         imp.close_input_file()
-        self.assertFalse(hasattr(imp, "input_reader"))
-        self.assertFalse(hasattr(imp, "input_file"))
+        self.assertIsNone(imp.input_reader)
+        self.assertIsNone(imp.input_file)
 
     def test_get_source_objects(self):
         model = self.app.model