diff --git a/windows/pe_parse.py b/windows/pe_parse.py
index b677626..a19eb74 100644
--- a/windows/pe_parse.py
+++ b/windows/pe_parse.py
@@ -3,6 +3,7 @@ import windows
 import windows.hooks as hooks
 import windows.utils as utils
 
+import windows.generated_def as gdef
 from windows.generated_def.winstructs import *
 from windows.utils import transform_ctypes_fields
 import windows.remotectypes as rctypes
@@ -38,9 +39,9 @@ def get_pe_bitness(baseaddr, target):
     # We can force bitness as the field we access are bitness-independant
     pe = GetPEFile(baseaddr, target, force_bitness=32)
     machine = pe.get_NT_HEADER().FileHeader.Machine
-    if machine == 0x14c:
+    if machine == gdef.IMAGE_FILE_MACHINE_I386:
         return 32
-    elif machine == 0x8664:
+    elif machine in (gdef.IMAGE_FILE_MACHINE_AMD64, gdef.IMAGE_FILE_MACHINE_ARM64):
         return 64
     else:
         raise ValueError("Unknow PE target machine <0x{0:x}>".format(machine))
diff --git a/windows/winobject/process.py b/windows/winobject/process.py
index 1d8facd..397fd99 100644
--- a/windows/winobject/process.py
+++ b/windows/winobject/process.py
@@ -95,9 +95,7 @@ class Process(utils.AutoHandle):
 
         :returns: :class:`int` -- 32 or 64
 		"""
-        if windows.system.bitness == 32:
-            return 32
-        if self.is_wow_64:
+        if windows.system.bitness == 32 or self.is_wow_64:
             return 32
         return 64
 
@@ -609,10 +607,10 @@ class Thread(utils.AutoHandle):
 class CurrentThread(Thread):
     """The current thread"""
 
-    get_teb_code_by_bitness = {
-        32: x86.assemble("mov eax, fs:[0x18]; ret"),
-        64: x64.assemble("mov rax, gs:[0x30]; ret")
-
+    get_teb_code_by_architecture = {
+        gdef.IMAGE_FILE_MACHINE_I386: x86.assemble("mov eax, fs:[0x18]; ret"),
+        gdef.IMAGE_FILE_MACHINE_AMD64: x64.assemble("mov rax, gs:[0x30]; ret"),
+        gdef.IMAGE_FILE_MACHINE_ARM64: x64.assemble("mov x0, x18; ret")
     }
 
     @property #It's not a fixedproperty because executing thread might change
@@ -625,7 +623,7 @@ class CurrentThread(Thread):
 
     @property #It's not a fixedproperty because executing thread might change
     def teb_base(self):
-        get_teb_base_code = self.get_teb_code_by_bitness[self.owner.bitness]
+        get_teb_base_code = self.get_teb_code_by_architecture[self.owner.architecture]
         return self.owner.execute(get_teb_base_code)
 
     @property