--- xnu/xnu-124.13/libkern/c++/OSNumber.cpp
+++ xnu/xnu-344.26/libkern/c++/OSNumber.cpp
@@ -21,16 +21,23 @@
  */
 /* IOOffset.m created by rsulack on Wed 17-Sep-1997 */
 
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+extern int sscanf(const char *input, const char *fmt, ...);
+__END_DECLS
+
 #include <libkern/c++/OSNumber.h>
 #include <libkern/c++/OSString.h>
 #include <libkern/c++/OSSerialize.h>
 #include <libkern/c++/OSLib.h>
 
-#define sizeMask ((1ULL << (size)) - 1)
+#define sizeMask (~0ULL >> (64 - size))
 
 #define super OSObject
 
 OSDefineMetaClassAndStructors(OSNumber, OSObject)
+
 OSMetaClassDefineReservedUnused(OSNumber, 0);
 OSMetaClassDefineReservedUnused(OSNumber, 1);
 OSMetaClassDefineReservedUnused(OSNumber, 2);