Index: abi/include/_bits/uchar.h
===================================================================
--- abi/include/_bits/uchar.h	(revision 5b19d806b26e4a267739e5ac28bbe9194259b766)
+++ abi/include/_bits/uchar.h	(revision dcef1127074a0bc848a38cc3831924924320c130)
@@ -38,5 +38,12 @@
 #include <stdint.h>
 
+/*
+ * char8_t became part of C++ with C++20.
+ * It is part of C23 hence we define it for C compilations only.
+ */
+#ifndef __cplusplus
 typedef uint8_t char8_t;
+#endif
+
 typedef uint32_t char32_t;