--- a/python/pypngtile.pyx	Sun Sep 14 16:26:38 2014 +0300
+++ b/python/pypngtile.pyx	Sun Sep 14 17:19:28 2014 +0300
@@ -32,7 +32,7 @@
 CACHE_STALE     = PT_CACHE_STALE
 CACHE_INCOMPAT  = PT_CACHE_INCOMPAT
 
-class Error (BaseException) :
+class Error (Exception) :
     """
         Base class for errors raised by pypngtile.
     """