diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index dfdc711..7398dc2 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -77,7 +77,7 @@
 int Py_VerboseFlag; /* Needed by import.c */
 int Py_InteractiveFlag; /* Needed by Py_FdIsInteractive() below */
 int Py_NoSiteFlag; /* Suppress 'import site' */
-int Py_UseClassExceptionsFlag; /* Needed by bltinmodule.c */
+int Py_UseClassExceptionsFlag = 1; /* Needed by bltinmodule.c */
 
 static int initialized = 0;