diff --git a/check_dist.sh b/check_dist.sh
new file mode 100644
index 0000000..782dc13
--- /dev/null
+++ b/check_dist.sh
@@ -0,0 +1,13 @@
+set -e
+#rmvirtualenv temp
+#mkvirtualenv temp
+bash create_dist.sh
+pip install .
+cd ~/Downloads
+rm -Rf py_mock_data_test_dist
+mkdir py_mock_data_test_dist
+cd py_mock_data_test_dist
+cp ~/projects/py-data-mock/requirements_test_dist.txt .
+pip install -r requirements_test_dist.txt
+cp -R $PROJECTS_DIR/py-data-mock/unittests .
+bash unittests/test_all.sh
diff --git a/data_mock/__init__.py b/data_mock/__init__.py
index 6e040bf..5b6c1a1 100644
--- a/data_mock/__init__.py
+++ b/data_mock/__init__.py
@@ -1,3 +1,3 @@
-__version__ = "0.0.2"
+__version__ = "0.0.3"
 __author__ = 'Henry Tremblay'
 
diff --git a/data_mock/google/cloud/bigquery/client.py b/data_mock/google/cloud/bigquery/client.py
index 6de8fdb..bba47a3 100644
--- a/data_mock/google/cloud/bigquery/client.py
+++ b/data_mock/google/cloud/bigquery/client.py
@@ -1,9 +1,9 @@
-from . import exceptions
 from .  import table as _table
 from .job import query as job_query
 from . import retry as retries
 from . import dataset as _dataset
 import data_mock.mock_helpers.provider as provider
+import data_mock.exceptions as exceptions
 
 from typing import Union, Optional
 
@@ -49,7 +49,10 @@ def query(self, query,
             if not data:
                 raise exceptions.InvalidMockData(f'{key} not found in registered_data')
         else:
-            data, m = self.data_provider.get_data('default')
+            try:
+                data, m = self.data_provider.get_data('default')
+            except TypeError:
+                raise exceptions.InvalidMockData(f'bad class')
         return _table.RowIterator(data = data, m = m)
 
     def create_table(self,
diff --git a/data_mock/mock_helpers/provider.py b/data_mock/mock_helpers/provider.py
index 86c6906..28c6b9a 100644
--- a/data_mock/mock_helpers/provider.py
+++ b/data_mock/mock_helpers/provider.py
@@ -3,6 +3,7 @@
 import data_mock.exceptions
 from data_mock.google.cloud import bigquery
 #from bigquery import SchemaField
+import types
 
 class QueryResultsFromList:
 
@@ -54,6 +55,10 @@ def get_data(self, key:str) -> Union[None, types.GeneratorType]:
             return None, None
         if not  hasattr(self.dict[key], 'query_results'):
             raise data_mock.exceptions.InvalidMockData('object does not have query_results')
+        if not isinstance(self.dict[key].query_results, types.MethodType):
+            msg = '"query_results" is  not a method; did you pass the class rather than class()?'
+            raise data_mock.exceptions.InvalidMockData(msg)
+
 
         return self.dict[key].query_results()
 
diff --git a/setup.py b/setup.py
index 5594128..08255f8 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@
 
 setup(
     name='py-data-mock',
-    version='0.0.2',    
+    version='0.0.3',    
     scripts=['data_mock/scripts/mkmock.py'],
     description='Mock Data',
     url='https://github.com/paulhtremblay/py-data-mock',
@@ -10,7 +10,7 @@
     author_email='paulhtremblay@gmail.com',
     license='GNU GENERAL PUBLIC LICENSE',
     packages=['data_mock/google/cloud/bigquery/job', 'data_mock/google/cloud/bigquery',
-        'data_mock/google/cloud/storage','data_mock/mock_helpers',
+        'data_mock/google/cloud/storage','data_mock/mock_helpers', 'data_mock',
         ],
      classifiers=[
         'Programming Language :: Python :: 3',
diff --git a/unittests/test_client.py b/unittests/test_client.py
index 16f1f35..b7c1750 100644
--- a/unittests/test_client.py
+++ b/unittests/test_client.py
@@ -116,6 +116,13 @@ def query_results(self):
         else:
             return self.gen_func1(), {'total_rows':10}
 
+class BadClass1:
+    def query_results(self):
+        return None
+
+
+
+
 class TestResults(unittest.TestCase):
 
     def setUp(self):
@@ -206,6 +213,47 @@ def test_not_a_list_in_list_data_raises_InvalidData(self):
                 data_mock.exceptions.InvalidMockData, 
                 bigquery.Client, mock_data = data
                  )
+    def test_data_not_a_class_raises_InvalidData(self):
+        class Client(bigquery.Client):
+
+            def register_initial_mock_data(self):
+                self.data_provider.add_data(data =ProviderData1, tag = 'default')
+        client = Client()
+        self.assertRaises(
+                data_mock.exceptions.InvalidMockData, 
+                client.query, query = ''
+                 )
+
+    def test_data_not_a_class2_raises_InvalidData(self):
+        class Client(bigquery.Client):
+
+            def register_initial_mock_data(self):
+                self.data_provider.add_data(data =1, tag = 'default')
+        client = Client()
+        self.assertRaises(
+                data_mock.exceptions.InvalidMockData, 
+                client.query, query = ''
+                 )
+
+    def test_data_not_a_class3_raises_InvalidData(self):
+        class Client(bigquery.Client):
+            def query_results(self):
+                return None
+
+            def register_initial_mock_data(self):
+                self.data_provider.add_data(data =BadClass1(), tag = 'default')
+
+        c = Client()
+        self.assertRaises(data_mock.exceptions.InvalidMockData,c.query, query = '')
+
+    def test_data_not_registered_raises_InvalidData(self):
+        client = bigquery.Client()
+        sql = """
+
+            py-bigquery-mock-register: data1
+        """
+        self.assertRaises(data_mock.exceptions.InvalidMockData,client.query, query = sql)
+
 
     def test_create_table_succeeds(self):
         table_id = 'project.dataset_id.tabele_id'