restore namespacing of pyexpat symbols (closes #19186)
diff --git a/Modules/expat/expat_external.h b/Modules/expat/expat_external.h
index 2c03284..f337e1c 100644
--- a/Modules/expat/expat_external.h
+++ b/Modules/expat/expat_external.h
@@ -7,6 +7,10 @@
/* External API definitions */
+/* Namespace external symbols to allow multiple libexpat version to
+ co-exist. */
+#include "pyexpatns.h"
+
#if defined(_MSC_EXTENSIONS) && !defined(__BEOS__) && !defined(__CYGWIN__)
#define XML_USE_MSC_EXTENSIONS 1
#endif