diff --git a/_msbuild.py b/_msbuild.py
index 9440010..4830751 100644
--- a/_msbuild.py
+++ b/_msbuild.py
@@ -88,6 +88,7 @@ class ResourceFile(CSourceFile):
     CFunction('get_current_package'),
     CFunction('read_alias_package'),
     CFunction('broadcast_settings_change'),
+    CFunction('get_processor_architecture'),
     source='src/_native',
     RootNamespace='_native',
 )
diff --git a/_msbuild_test.py b/_msbuild_test.py
index 949a4ec..2b28a4b 100644
--- a/_msbuild_test.py
+++ b/_msbuild_test.py
@@ -54,6 +54,7 @@
         CFunction('get_current_package'),
         CFunction('read_alias_package'),
         CFunction('broadcast_settings_change'),
+        CFunction('get_processor_architecture'),
         source='src/_native',
     ),
     DllPackage('_shellext_test',
diff --git a/src/_native/misc.cpp b/src/_native/misc.cpp
index 37b7320..070c0cf 100644
--- a/src/_native/misc.cpp
+++ b/src/_native/misc.cpp
@@ -233,4 +233,25 @@ PyObject *broadcast_settings_change(PyObject *, PyObject *, PyObject *) {
     return Py_GetConstant(Py_CONSTANT_NONE);
 }
 
+typedef enum {
+    CPU_X86     = 0,
+    CPU_X86_64  = 9,
+    CPU_ARM     = 5,
+    CPU_ARM64   = 12,
+    CPU_UNKNOWN = 0xffff
+} CpuArchitecture;
+
+PyObject *get_processor_architecture(PyObject *, PyObject *, PyObject *) {
+    SYSTEM_INFO system_info;
+    GetNativeSystemInfo(&system_info);
+    
+    switch (system_info.wProcessorArchitecture) {
+        case CPU_X86: return PyUnicode_FromString("-32");
+        case CPU_X86_64: return PyUnicode_FromString("-64");
+        case CPU_ARM: return PyUnicode_FromString("-arm");
+        case CPU_ARM64: return PyUnicode_FromString("-arm64");
+        default: return PyUnicode_FromString("-64"); // x86-64
+    }
+}
+
 }
diff --git a/src/manage/commands.py b/src/manage/commands.py
index ec57c09..0043492 100644
--- a/src/manage/commands.py
+++ b/src/manage/commands.py
@@ -443,6 +443,9 @@ def __init__(self, args, root=None):
                 _set_args.add(k)
 
         if not self.default_platform:
+            from _native import get_processor_architecture
+            LOGGER.debug("Get CPU architecture, its prefix is %s", get_processor_architecture())
+
             # Currently, we always default to -64.
             self.default_platform = "-64"