diff --git a/include/pocketpy/interpreter/gc.h b/include/pocketpy/interpreter/gc.h
index 6f8fa221..d7844121 100644
--- a/include/pocketpy/interpreter/gc.h
+++ b/include/pocketpy/interpreter/gc.h
@@ -28,8 +28,8 @@ void pk_ManagedHeap__collect_if_needed(pk_ManagedHeap* self);
 int pk_ManagedHeap__collect(pk_ManagedHeap* self);
 int pk_ManagedHeap__sweep(pk_ManagedHeap* self);
 
-PyObject* pk_ManagedHeap__new(pk_ManagedHeap* self, Type type, int slots, int size);
-PyObject* pk_ManagedHeap__gcnew(pk_ManagedHeap* self, Type type, int slots, int size);
+PyObject* pk_ManagedHeap__new(pk_ManagedHeap* self, py_Type type, int slots, int size);
+PyObject* pk_ManagedHeap__gcnew(pk_ManagedHeap* self, py_Type type, int slots, int size);
 
 // external implementation
 void pk_ManagedHeap__mark(pk_ManagedHeap* self);
diff --git a/include/pocketpy/interpreter/vm.h b/include/pocketpy/interpreter/vm.h
index 6b00cbb4..7ac13f62 100644
--- a/include/pocketpy/interpreter/vm.h
+++ b/include/pocketpy/interpreter/vm.h
@@ -10,7 +10,7 @@ extern "C" {
 
 typedef struct pk_TypeInfo{
     py_Name name;
-    Type base;
+    py_Type base;
 
     PyVar self;      // the type object itself
     PyVar module;    // the module where the type is defined
@@ -38,7 +38,7 @@ typedef struct pk_TypeInfo{
     py_CFunction on_end_subclass;   // for enum module
 } pk_TypeInfo;
 
-void pk_TypeInfo__ctor(pk_TypeInfo* self, py_Name name, Type base, PyObject* obj, const PyVar* module, bool subclass_enabled);
+void pk_TypeInfo__ctor(pk_TypeInfo* self, py_Name name, py_Type base, PyObject* obj, const PyVar* module, bool subclass_enabled);
 void pk_TypeInfo__dtor(pk_TypeInfo* self);
 
 typedef struct pk_VM {
@@ -91,7 +91,7 @@ typedef enum pk_FrameResult{
 
 pk_FrameResult pk_VM__run_top_frame(pk_VM* self);
 
-Type pk_VM__new_type(pk_VM* self, const char* name, Type base, const PyVar* module, bool subclass_enabled);
+py_Type pk_VM__new_type(pk_VM* self, const char* name, py_Type base, const PyVar* module, bool subclass_enabled);
 
 #ifdef __cplusplus
 }
diff --git a/include/pocketpy/objects/base.h b/include/pocketpy/objects/base.h
index e6a28aa2..f30066c4 100644
--- a/include/pocketpy/objects/base.h
+++ b/include/pocketpy/objects/base.h
@@ -13,10 +13,10 @@
 extern "C" {
 #endif
 
-typedef int16_t Type;
+typedef int16_t py_Type;
 
 typedef struct PyVar{
-    Type type;
+    py_Type type;
     bool is_ptr;
     int extra;
     union {
@@ -39,23 +39,23 @@ typedef struct PyVar{
 static_assert(sizeof(PyVar) == 16, "sizeof(PyVar) != 16");
 
 /* predefined vars */
-static const Type tp_object = {1}, tp_type = {2};
-static const Type tp_int = {3}, tp_float = {4}, tp_bool = {5}, tp_str = {6};
-static const Type tp_list = {7}, tp_tuple = {8};
-static const Type tp_slice = {9}, tp_range = {10}, tp_module = {11};
-static const Type tp_function = {12}, tp_nativefunc = {13}, tp_bound_method = {14};
-static const Type tp_super = {15}, tp_exception = {16}, tp_bytes = {17}, tp_mappingproxy = {18};
-static const Type tp_dict = {19}, tp_property = {20}, tp_star_wrapper = {21};
-static const Type tp_staticmethod = {22}, tp_classmethod = {23};
-static const Type tp_none_type = {24}, tp_not_implemented_type = {25};
-static const Type tp_ellipsis = {26};
-static const Type tp_op_call = {27}, tp_op_yield = {28};
-static const Type tp_syntax_error = {29}, tp_stop_iteration = {30};
+static const py_Type tp_object = {1}, tp_type = {2};
+static const py_Type tp_int = {3}, tp_float = {4}, tp_bool = {5}, tp_str = {6};
+static const py_Type tp_list = {7}, tp_tuple = {8};
+static const py_Type tp_slice = {9}, tp_range = {10}, tp_module = {11};
+static const py_Type tp_function = {12}, tp_nativefunc = {13}, tp_bound_method = {14};
+static const py_Type tp_super = {15}, tp_exception = {16}, tp_bytes = {17}, tp_mappingproxy = {18};
+static const py_Type tp_dict = {19}, tp_property = {20}, tp_star_wrapper = {21};
+static const py_Type tp_staticmethod = {22}, tp_classmethod = {23};
+static const py_Type tp_none_type = {24}, tp_not_implemented_type = {25};
+static const py_Type tp_ellipsis = {26};
+static const py_Type tp_op_call = {27}, tp_op_yield = {28};
+static const py_Type tp_syntax_error = {29}, tp_stop_iteration = {30};
 
 PK_INLINE bool PyVar__is_null(const PyVar* self) { return self->type == 0; }
 PK_INLINE int64_t PyVar__hash(const PyVar* self) { return self->extra + self->_i64; }
 
-PK_INLINE void PyVar__ctor(PyVar* self, Type type, PyObject* obj){
+PK_INLINE void PyVar__ctor(PyVar* self, py_Type type, PyObject* obj){
     self->type = type;
     self->is_ptr = true;
     self->_obj = obj;
diff --git a/include/pocketpy/objects/object.h b/include/pocketpy/objects/object.h
index 1824fb2d..afa61c35 100644
--- a/include/pocketpy/objects/object.h
+++ b/include/pocketpy/objects/object.h
@@ -8,7 +8,7 @@ extern "C" {
 #endif
 
 typedef struct PyObject{
-    Type type;          // we have a duplicated type here for convenience
+    py_Type type;          // we have a duplicated type here for convenience
     bool gc_is_large;
     bool gc_marked;
     int slots;          // number of slots in the object
@@ -28,7 +28,7 @@ void* PyObject__value(PyObject* self);
 
 #define PK_OBJ_HEADER_SIZE(slots) ((slots)>=0 ? 8+sizeof(PyVar)*(slots) : 8+sizeof(pk_NameDict))
 
-PyObject* PyObject__new(Type type, int slots, int size);
+PyObject* PyObject__new(py_Type type, int slots, int size);
 void PyObject__delete(PyObject* self);
 
 PK_INLINE PyVar PyVar__fromobj(PyObject* obj){
diff --git a/include/pocketpy/pocketpy.h b/include/pocketpy/pocketpy.h
index 9808a9ea..4fb6f050 100644
--- a/include/pocketpy/pocketpy.h
+++ b/include/pocketpy/pocketpy.h
@@ -8,14 +8,14 @@ typedef struct PyObject PyObject;
 typedef struct PyVar PyVar;
 typedef struct pk_VM pk_VM;
 typedef uint16_t py_Name;
-typedef int16_t Type;
+typedef int16_t py_Type;
 typedef PyVar* py_Ref;
 typedef int (*py_CFunction)(const py_Ref, int);
 
 typedef struct py_Str py_Str;
 
 typedef struct py_Error{
-    Type type;
+    py_Type type;
 } py_Error;
 
 typedef enum BindType {
@@ -139,9 +139,9 @@ int py_tofloat(py_Ref, double* out);
 int py_tostr(py_Ref, py_Str** out);
 int py_tobool(py_Ref, bool* out);
 
-bool py_istype(const py_Ref, Type);
-bool py_isinstance(const py_Ref obj, Type type);
-bool py_issubclass(Type derived, Type base);
+bool py_istype(const py_Ref, py_Type);
+bool py_isinstance(const py_Ref obj, py_Type type);
+bool py_issubclass(py_Type derived, py_Type base);
 
 #ifdef __cplusplus
 }
diff --git a/src/interpreter/gc.c b/src/interpreter/gc.c
index 94f0d5c7..1ea28ead 100644
--- a/src/interpreter/gc.c
+++ b/src/interpreter/gc.c
@@ -88,20 +88,20 @@ int pk_ManagedHeap__sweep(pk_ManagedHeap *self){
     return freed;
 }
 
-PyObject* pk_ManagedHeap__new(pk_ManagedHeap *self, Type type, int slots, int size){
+PyObject* pk_ManagedHeap__new(pk_ManagedHeap *self, py_Type type, int slots, int size){
     PyObject* obj = PyObject__new(type, slots, size);
     c11_vector__push(PyObject*, &self->no_gc, obj);
     return obj;
 }
 
-PyObject* pk_ManagedHeap__gcnew(pk_ManagedHeap *self, Type type, int slots, int size){
+PyObject* pk_ManagedHeap__gcnew(pk_ManagedHeap *self, py_Type type, int slots, int size){
     PyObject* obj = PyObject__new(type, slots, size);
     c11_vector__push(PyObject*, &self->gen, obj);
     self->gc_counter++;
     return obj;
 }
 
-PyObject* PyObject__new(Type type, int slots, int size){
+PyObject* PyObject__new(py_Type type, int slots, int size){
     assert(slots >= 0 || slots == -1);
     PyObject* self;
     size += PK_OBJ_HEADER_SIZE(slots);
diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index 44dbb587..58e6b1c9 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -17,7 +17,7 @@ static void pk_default_stderr(const char* s){
     fflush(stderr);
 }
 
-void pk_TypeInfo__ctor(pk_TypeInfo *self, py_Name name, Type base, PyObject* obj, const PyVar* module, bool subclass_enabled){
+void pk_TypeInfo__ctor(pk_TypeInfo *self, py_Name name, py_Type base, PyObject* obj, const PyVar* module, bool subclass_enabled){
     memset(self, 0, sizeof(pk_TypeInfo));
     
     self->name = name;
@@ -172,7 +172,7 @@ void pk_VM__ctor(pk_VM* self){
     self->builtins = *py_newmodule("builtins", NULL);
     
     /* Setup Public Builtin Types */
-    Type public_types[] = {
+    py_Type public_types[] = {
         tp_object, tp_type,
         tp_int, tp_float, tp_bool, tp_str,
         tp_list, tp_tuple,
@@ -182,7 +182,7 @@ void pk_VM__ctor(pk_VM* self){
     };
 
     for(int i=0; i<PK_ARRAY_COUNT(public_types); i++){
-        Type t = public_types[i];
+        py_Type t = public_types[i];
         pk_TypeInfo* ti = c11__at(pk_TypeInfo, &self->types, t);
         py_setdict(&self->builtins, ti->name, &ti->self);
     }
@@ -220,11 +220,11 @@ pk_FrameResult pk_VM__run_top_frame(pk_VM* self){
     return RES_RETURN;
 }
 
-Type pk_VM__new_type(pk_VM* self, const char* name, Type base, const PyVar* module, bool subclass_enabled){
-    Type type = self->types.count;
+py_Type pk_VM__new_type(pk_VM* self, const char* name, py_Type base, const PyVar* module, bool subclass_enabled){
+    py_Type type = self->types.count;
     pk_TypeInfo* ti = c11_vector__emplace(&self->types);
-    PyObject* typeobj = pk_ManagedHeap__gcnew(&self->heap, tp_type, 0, sizeof(Type));
-    Type* value = PyObject__value(typeobj);
+    PyObject* typeobj = pk_ManagedHeap__gcnew(&self->heap, tp_type, 0, sizeof(py_Type));
+    py_Type* value = PyObject__value(typeobj);
     *value = type;
     pk_TypeInfo__ctor(ti, py_name(name), base, typeobj, module, subclass_enabled);
     return type;