diff -r b2efb7df637b discover.py
--- a/discover.py	Thu Mar 24 00:31:02 2011 -0400
+++ b/discover.py	Thu Nov 28 12:02:19 2013 +0000
@@ -82,7 +82,11 @@
     """
     testMethodPrefix = 'test'
     sortTestMethodsUsing = cmp
-    suiteClass = unittest.TestSuite
+    try:
+        import unittest2
+        suiteClass = unittest2.TestSuite
+    except ImportError:
+        suiteClass = unittest.TestSuite
     _top_level_dir = None
 
     def loadTestsFromTestCase(self, testCaseClass):