diff --git a/nsprpub/TAG-INFO b/nsprpub/TAG-INFO
index a46b9af51ab5..d4ab0f2570d8 100644
--- a/nsprpub/TAG-INFO
+++ b/nsprpub/TAG-INFO
@@ -1 +1 @@
-6e31156d7002
+34274ae8c85e
diff --git a/nsprpub/config/prdepend.h b/nsprpub/config/prdepend.h
index 6c66b37ca0fc..e49e92677e3e 100644
--- a/nsprpub/config/prdepend.h
+++ b/nsprpub/config/prdepend.h
@@ -10,4 +10,3 @@
  */
 
 #error "Do not include this header file."
-
diff --git a/nsprpub/configure.in b/nsprpub/configure.in
index bd70a7e06972..cbd22b42e840 100644
--- a/nsprpub/configure.in
+++ b/nsprpub/configure.in
@@ -2106,6 +2106,10 @@ tools are selected during the Xcode/Developer Tools installation.])
 	    AC_DEFINE(_AMD64_)
 	    USE_64=1
 	    ;;
+    aarch64)
+	    AC_DEFINE(_ARM64_)
+	    USE_64=1
+	    ;;
     ia64)
 	    AC_DEFINE(_IA64_)
 	    USE_64=1
diff --git a/nsprpub/pr/include/md/_win95.cfg b/nsprpub/pr/include/md/_win95.cfg
index 1e693cc68ca4..7c379fce709b 100644
--- a/nsprpub/pr/include/md/_win95.cfg
+++ b/nsprpub/pr/include/md/_win95.cfg
@@ -214,6 +214,55 @@
 #define PR_BYTES_PER_WORD_LOG2  2
 #define PR_BYTES_PER_DWORD_LOG2 3
 
+#elif defined(_M_ARM64) || defined(_ARM64_)
+
+#define IS_LITTLE_ENDIAN 1
+#undef  IS_BIG_ENDIAN
+#define IS_64
+
+#define PR_BYTES_PER_BYTE   1
+#define PR_BYTES_PER_SHORT  2
+#define PR_BYTES_PER_INT    4
+#define PR_BYTES_PER_INT64  8
+#define PR_BYTES_PER_LONG   4
+#define PR_BYTES_PER_FLOAT  4
+#define PR_BYTES_PER_WORD	8
+#define PR_BYTES_PER_DWORD	8
+#define PR_BYTES_PER_DOUBLE 8
+
+#define PR_BITS_PER_BYTE    8
+#define PR_BITS_PER_SHORT   16
+#define PR_BITS_PER_INT     32
+#define PR_BITS_PER_INT64   64
+#define PR_BITS_PER_LONG    32
+#define PR_BITS_PER_FLOAT   32
+#define PR_BITS_PER_WORD	64
+#define PR_BITS_PER_DWORD	64
+#define PR_BITS_PER_DOUBLE  64
+
+#define PR_BITS_PER_BYTE_LOG2   3
+#define PR_BITS_PER_SHORT_LOG2  4
+#define PR_BITS_PER_INT_LOG2    5
+#define PR_BITS_PER_INT64_LOG2  6
+#define PR_BITS_PER_LONG_LOG2   5
+#define PR_BITS_PER_FLOAT_LOG2  5
+#define PR_BITS_PER_WORD_LOG2	6
+#define PR_BITS_PER_DWORD_LOG2	6
+#define PR_BITS_PER_DOUBLE_LOG2 6
+
+#define PR_ALIGN_OF_SHORT   2
+#define PR_ALIGN_OF_INT     4
+#define PR_ALIGN_OF_LONG    4
+#define PR_ALIGN_OF_INT64   8
+#define PR_ALIGN_OF_FLOAT   4
+#define PR_ALIGN_OF_WORD	8
+#define PR_ALIGN_OF_DWORD	8
+#define PR_ALIGN_OF_DOUBLE  8
+#define PR_ALIGN_OF_POINTER 8
+
+#define PR_BYTES_PER_WORD_LOG2	3
+#define PR_BYTES_PER_DWORD_LOG2	3
+
 #else /* defined(_M_IX86) || defined(_X86_) */
 
 #error unknown processor architecture
diff --git a/nsprpub/pr/include/md/_win95.h b/nsprpub/pr/include/md/_win95.h
index 04f811d37d84..24e537bb74b5 100644
--- a/nsprpub/pr/include/md/_win95.h
+++ b/nsprpub/pr/include/md/_win95.h
@@ -26,6 +26,8 @@
 #define _PR_SI_ARCHITECTURE   "ia64"
 #elif defined(_M_ARM) || defined(_ARM_)
 #define _PR_SI_ARCHITECTURE   "arm"
+#elif defined(_M_ARM64)
+#define _PR_SI_ARCHITECTURE   "aarch64"
 #else
 #error unknown processor architecture
 #endif