diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index b109ba7..fb7e223 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -16,10 +16,13 @@
 */
 #if defined(MS_WINDOWS) && defined(HAVE_USABLE_WCHAR_T)
 const char *Py_FileSystemDefaultEncoding = "mbcs";
+const int Py_HasFileSystemDefaultEncoding = 1;
 #elif defined(__APPLE__)
 const char *Py_FileSystemDefaultEncoding = "utf-8";
+const int Py_HasFileSystemDefaultEncoding = 1;
 #else
 const char *Py_FileSystemDefaultEncoding = NULL; /* use default */
+const int Py_HasFileSystemDefaultEncoding = 0;
 #endif
 
 static PyObject *