--- nspr/pr/include/md/_winnt.h	2022-05-25 15:34:56.000000000 -0600
+++ nspr-c/pr/include/md/_winnt.h	2022-07-28 21:35:40.397496900 -0600
@@ -38,6 +38,8 @@
 #define _PR_SI_ARCHITECTURE   "x86-64"
 #elif defined(_M_IA64) || defined(_IA64_)
 #define _PR_SI_ARCHITECTURE   "ia64"
+#elif defined(_M_ARM64)
+#define _PR_SI_ARCHITECTURE   "aarch64"
 #else
 #error unknown processor architecture
 #endif