diff --git a/csscompressor/tests/base.py b/csscompressor/tests/base.py
index 5da2cf6..75d99f1 100644
--- a/csscompressor/tests/base.py
+++ b/csscompressor/tests/base.py
@@ -8,8 +8,10 @@
 
 from csscompressor import compress
 
+import unittest
 
-class BaseTest:
+
+class BaseTest(unittest.TestCase):
     def _test(self, input, output):
         result = compress(input)
         if result != output.strip():