diff --git a/windows/winobject/process.py b/windows/winobject/process.py
index 0873442..66999a5 100644
--- a/windows/winobject/process.py
+++ b/windows/winobject/process.py
@@ -106,12 +106,19 @@ class Process(utils.AutoHandle):
         # Syswow2 will exactly tell us the architecture
         if windows.winproxy.is_implemented(windows.winproxy.IsWow64Process2):
             process_machine, native_machine = self.is_wow_64_2
-            try:
-                return utils.image_file_machine_to_processor_architecture(process_machine)
-            except KeyError as e:
-                raise ValueError("Unknown IsWow64Process2(process_machine:#x) -> {0}".format(process_machine))
+            if process_machine != gdef.PROCESSOR_ARCHITECTURE_UNKNOWN:
+                try:
+                    return utils.image_file_machine_to_processor_architecture(process_machine)
+                except KeyError as e:
+                    raise ValueError("Unknown IsWow64Process2(process_machine:#x) -> {0}".format(process_machine))
 
-        # No IsWow64Process2 -> No ARM64
+            if windows.system.architecture == gdef.PROCESSOR_ARCHITECTURE_ARM64:
+                # May be ARM64 or AMD64 as X64TA64 is not considered WOW64
+                machine_archi = gdef.PROCESS_MACHINE_INFORMATION()
+                windows.winproxy.GetProcessInformation(self.handle, gdef.ProcessMachineTypeInfo, machine_archi)
+                return utils.image_file_machine_to_processor_architecture(machine_archi.ProcessMachine)
+
+        # No IsWow64Process2 -> No ARM
         # So its up on x86 -> x64 based on process bitness
         if self.bitness == 32:
             return gdef.PROCESSOR_ARCHITECTURE_INTEL