diff --git a/Include/pydebug.h b/Include/pydebug.h
index 1cbb342..70c88f6 100644
--- a/Include/pydebug.h
+++ b/Include/pydebug.h
@@ -7,6 +7,7 @@
 
 PyAPI_DATA(int) Py_DebugFlag;
 PyAPI_DATA(int) Py_VerboseFlag;
+PyAPI_DATA(int) Py_QuietFlag;
 PyAPI_DATA(int) Py_InteractiveFlag;
 PyAPI_DATA(int) Py_InspectFlag;
 PyAPI_DATA(int) Py_OptimizeFlag;