diff --git a/src/hotspot/os_cpu/windows_aarch64/javaThread_windows_aarch64.cpp b/src/hotspot/os_cpu/windows_aarch64/javaThread_windows_aarch64.cpp
index 8e97fa6b5c1..df434398deb 100644
--- a/src/hotspot/os_cpu/windows_aarch64/javaThread_windows_aarch64.cpp
+++ b/src/hotspot/os_cpu/windows_aarch64/javaThread_windows_aarch64.cpp
@@ -29,7 +29,7 @@
 
 frame JavaThread::pd_last_frame() {
   assert(has_last_Java_frame(), "must have last_Java_sp() when suspended");
-  vmassert(_anchor.last_Java_pc() != NULL, "not walkable");
+  vmassert(_anchor.last_Java_pc() != nullptr, "not walkable");
   frame f = frame(_anchor.last_Java_sp(), _anchor.last_Java_fp(), _anchor.last_Java_pc());
   f.set_sp_is_trusted();
   return f;
@@ -61,15 +61,15 @@ bool JavaThread::pd_get_top_frame(frame* fr_addr, void* ucontext, bool isInJava)
   // if we were running Java code when SIGPROF came in.
   if (isInJava) {
     frame ret_frame = os::fetch_frame_from_context(ucontext);
-    if (ret_frame.pc() == NULL || ret_frame.sp() == NULL ) {
+    if (ret_frame.pc() == nullptr || ret_frame.sp() == nullptr ) {
       // CONTEXT wasn't useful
       return false;
     }
 
     if (!ret_frame.safe_for_sender(this)) {
 #if COMPILER2_OR_JVMCI
-      // C2 and JVMCI use ebp as a general register see if NULL fp helps
-      frame ret_frame2(ret_frame.sp(), NULL, ret_frame.pc());
+      // C2 and JVMCI use ebp as a general register see if null fp helps
+      frame ret_frame2(ret_frame.sp(), nullptr, ret_frame.pc());
       if (!ret_frame2.safe_for_sender(this)) {
         // nothing else to try if the frame isn't good
         return false;
diff --git a/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp b/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp
index b528ae56777..a4d9d2ae6c2 100644
--- a/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp
+++ b/src/hotspot/os_cpu/windows_aarch64/os_windows_aarch64.cpp
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2020, Microsoft Corporation. All rights reserved.
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -79,15 +79,15 @@ address os::fetch_frame_from_context(const void* ucVoid,
   address  epc;
   CONTEXT* uc = (CONTEXT*)ucVoid;
 
-  if (uc != NULL) {
+  if (uc != nullptr) {
     epc = (address)uc->Pc;
     if (ret_sp) *ret_sp = (intptr_t*)uc->Sp;
     if (ret_fp) *ret_fp = (intptr_t*)uc->Fp;
   } else {
     // construct empty ExtendedPC for return value checking
-    epc = NULL;
-    if (ret_sp) *ret_sp = (intptr_t *)NULL;
-    if (ret_fp) *ret_fp = (intptr_t *)NULL;
+    epc = nullptr;
+    if (ret_sp) *ret_sp = (intptr_t *)nullptr;
+    if (ret_fp) *ret_fp = (intptr_t *)nullptr;
   }
   return epc;
 }
@@ -117,7 +117,7 @@ bool os::win32::get_frame_at_stack_banging_point(JavaThread* thread,
     // more complex code with compiled code
     assert(!Interpreter::contains(pc), "Interpreted methods should have been handled above");
     CodeBlob* cb = CodeCache::find_blob(pc);
-    if (cb == NULL || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
+    if (cb == nullptr || !cb->is_nmethod() || cb->is_frame_complete_at(pc)) {
       // Not sure where the pc points to, fallback to default
       // stack overflow handling
       return false;
@@ -161,7 +161,7 @@ frame os::current_frame() {
 // helper functions for fatal error handler
 
 void os::print_context(outputStream *st, const void *context) {
-  if (context == NULL) return;
+  if (context == nullptr) return;
 
   const CONTEXT* uc = (const CONTEXT*)context;
 
@@ -207,7 +207,7 @@ void os::print_context(outputStream *st, const void *context) {
 }
 
 void os::print_tos_pc(outputStream *st, const void *context) {
-  if (context == NULL) return;
+  if (context == nullptr) return;
 
   const CONTEXT* uc = (const CONTEXT*)context;
 
@@ -225,7 +225,7 @@ void os::print_tos_pc(outputStream *st, const void *context) {
 }
 
 void os::print_register_info(outputStream *st, const void *context) {
- if (context == NULL) return;
+ if (context == nullptr) return;
 
   const CONTEXT* uc = (const CONTEXT*)context;
 
diff --git a/src/hotspot/os_cpu/windows_aarch64/vm_version_windows_aarch64.cpp b/src/hotspot/os_cpu/windows_aarch64/vm_version_windows_aarch64.cpp
index 37f32d3eb3e..3813287af05 100644
--- a/src/hotspot/os_cpu/windows_aarch64/vm_version_windows_aarch64.cpp
+++ b/src/hotspot/os_cpu/windows_aarch64/vm_version_windows_aarch64.cpp
@@ -53,11 +53,11 @@ void VM_Version::get_os_cpu_info() {
   }
 
   {
-    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL;
+    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = nullptr;
     DWORD returnLength = 0;
 
     // See https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getlogicalprocessorinformation
-    GetLogicalProcessorInformation(NULL, &returnLength);
+    GetLogicalProcessorInformation(nullptr, &returnLength);
     assert(GetLastError() == ERROR_INSUFFICIENT_BUFFER, "Unexpected return from GetLogicalProcessorInformation");
 
     buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION)os::malloc(returnLength, mtInternal);
@@ -81,9 +81,9 @@ void VM_Version::get_os_cpu_info() {
 
   {
     char* buf = ::getenv("PROCESSOR_IDENTIFIER");
-    if (buf && strstr(buf, "Ampere(TM)") != NULL) {
+    if (buf && strstr(buf, "Ampere(TM)") != nullptr) {
       _cpu = CPU_AMCC;
-    } else if (buf && strstr(buf, "Cavium Inc.") != NULL) {
+    } else if (buf && strstr(buf, "Cavium Inc.") != nullptr) {
       _cpu = CPU_CAVIUM;
     } else {
       log_info(os)("VM_Version: unknown CPU model");
@@ -100,7 +100,7 @@ void VM_Version::get_os_cpu_info() {
 }
 
 void VM_Version::get_compatible_board(char *buf, int buflen) {
-  assert(buf != NULL, "invalid argument");
+  assert(buf != nullptr, "invalid argument");
   assert(buflen >= 1, "invalid argument");
   *buf = '\0';
 }