diff --git a/src/api/python/z3printer.py b/src/api/python/z3printer.py
index d3dc43d3e..d1d85d30e 100644
--- a/src/api/python/z3printer.py
+++ b/src/api/python/z3printer.py
@@ -386,7 +386,7 @@ def seq3(args, lp='(', rp=')'):
     else:
         return group(indent(len(lp), compose(to_format(lp), seq(args), to_format(rp))))
 
-class StopPPException:
+class StopPPException(Exception):
     def __str__(self):
         return 'pp-interrupted'