#3525: 3.0 exception changes in tutorial.
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst
index bf2d0aa..4e2423f 100644
--- a/Doc/tutorial/classes.rst
+++ b/Doc/tutorial/classes.rst
@@ -671,7 +671,7 @@
 listing a derived class is not compatible with a base class).  For example, the
 following code will print B, C, D in that order::
 
-   class B:
+   class B(Exception):
        pass
    class C(B):
        pass