--- Libc/Libc-1669.40.2/include/_printf.h
+++ Libc/Libc-1725.40.4/include/_printf.h
@@ -25,6 +25,9 @@
 #define	__PRINTF_H_
 
 #include <sys/cdefs.h>
+#include <_bounds.h>
+
+_LIBC_SINGLE_BY_DEFAULT()
 
 #ifndef UNIFDEF_DRIVERKIT