diff --git a/tests/testsuite.py b/tests/testsuite.py
index 685b639..6eca4e1 100644
--- a/tests/testsuite.py
+++ b/tests/testsuite.py
@@ -6,6 +6,9 @@
 
 
 class TestInstrBuilder(unittest.TestCase):
+    def __str__(self):
+        return 'Z80IntrsBuilder'
+
     def runTest(self):
         TESTS = (
             (b'\xdd\xe5', 'push ix'),