Fixed an issue for decorating class methods
diff --git a/timeout_decorator/timeout_decorator.py b/timeout_decorator/timeout_decorator.py
index 466f33d..aadc586 100644
--- a/timeout_decorator/timeout_decorator.py
+++ b/timeout_decorator/timeout_decorator.py
@@ -73,7 +73,10 @@
                         signal.signal(signal.SIGALRM, old)
             return new_function
         else:
-            return _Timeout(function, timeout_exception, seconds)
+            @wraps(function)
+            def new_function(*args, **kwargs):
+                return _Timeout(function, timeout_exception, seconds)
+            return new_function
 
     return decorate