diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index 63408e3..4acfa65 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -91,7 +91,7 @@
         self.expected_regexp = expected_regexp
 
     def __enter__(self):
-        pass
+        return self
 
     def __exit__(self, exc_type, exc_value, tb):
         if exc_type is None: