diff --git a/box/test/genty/genty.py b/box/test/genty/genty.py
index <HASH>..<HASH> 100644
--- a/box/test/genty/genty.py
+++ b/box/test/genty/genty.py
@@ -46,7 +46,8 @@ def _expand_tests(target_cls):
     entries = dict(target_cls.__dict__.iteritems())
     for key, value in entries.iteritems():
         if key.startswith('test') and isinstance(value, types.FunctionType):
-            yield key, value
+            if not hasattr(value, 'genty_generated_test'):
+                yield key, value
 
 
 def _expand_datasets(test_functions):
Fix genty being used on a parent class and base class defined in separate files and run with a test runner like nose.

Genty needs to not collect tests that have already been genty_generated to avoid expanding already expanded tests.