diff --git a/include/pocketpy/interpreter/frame.h b/include/pocketpy/interpreter/frame.h
index ed9fd6cb..9cda5531 100644
--- a/include/pocketpy/interpreter/frame.h
+++ b/include/pocketpy/interpreter/frame.h
@@ -28,8 +28,8 @@ typedef struct UnwindTarget {
 UnwindTarget* UnwindTarget__new(UnwindTarget* next, int iblock, int offset);
 void UnwindTarget__delete(UnwindTarget* self);
 
-typedef struct Frame {
-    struct Frame* f_back;
+typedef struct py_Frame {
+    struct py_Frame* f_back;
     const CodeObject* co;
     py_StackRef p0;  // unwinding base
     py_GlobalRef module;
@@ -38,35 +38,35 @@ typedef struct Frame {
     bool is_locals_special;
     int ip;
     UnwindTarget* uw_list;
-} Frame;
+} py_Frame;
 
 typedef struct SourceLocation {
     SourceData_ src;
     int lineno;
 } SourceLocation;
 
-Frame* Frame__new(const CodeObject* co,
+py_Frame* Frame__new(const CodeObject* co,
                   py_StackRef p0,
                   py_GlobalRef module,
                   py_Ref globals,
                   py_Ref locals,
                   bool is_locals_special);
-void Frame__delete(Frame* self);
+void Frame__delete(py_Frame* self);
 
-int Frame__lineno(const Frame* self);
-int Frame__iblock(const Frame* self);
+int Frame__lineno(const py_Frame* self);
+int Frame__iblock(const py_Frame* self);
 
-int Frame__getglobal(Frame* self, py_Name name) PY_RAISE PY_RETURN;
-bool Frame__setglobal(Frame* self, py_Name name, py_TValue* val) PY_RAISE;
-int Frame__delglobal(Frame* self, py_Name name) PY_RAISE;
+int Frame__getglobal(py_Frame* self, py_Name name) PY_RAISE PY_RETURN;
+bool Frame__setglobal(py_Frame* self, py_Name name, py_TValue* val) PY_RAISE;
+int Frame__delglobal(py_Frame* self, py_Name name) PY_RAISE;
 
-py_Ref Frame__getclosure(Frame* self, py_Name name);
-py_StackRef Frame__getlocal_noproxy(Frame* self, py_Name name);
+py_Ref Frame__getclosure(py_Frame* self, py_Name name);
+py_StackRef Frame__getlocal_noproxy(py_Frame* self, py_Name name);
 
-int Frame__prepare_jump_exception_handler(Frame* self, ValueStack*);
+int Frame__prepare_jump_exception_handler(py_Frame* self, ValueStack*);
 
-UnwindTarget* Frame__find_unwind_target(Frame* self, int iblock);
-void Frame__set_unwind_target(Frame* self, py_TValue* sp);
+UnwindTarget* Frame__find_unwind_target(py_Frame* self, int iblock);
+void Frame__set_unwind_target(py_Frame* self, py_TValue* sp);
 
-void Frame__gc_mark(Frame* self);
-SourceLocation Frame__source_location(Frame* self);
\ No newline at end of file
+void Frame__gc_mark(py_Frame* self);
+SourceLocation Frame__source_location(py_Frame* self);
\ No newline at end of file
diff --git a/include/pocketpy/interpreter/generator.h b/include/pocketpy/interpreter/generator.h
index 55616d39..bc8a53cc 100644
--- a/include/pocketpy/interpreter/generator.h
+++ b/include/pocketpy/interpreter/generator.h
@@ -4,10 +4,10 @@
 #include "pocketpy/pocketpy.h"
 
 typedef struct Generator{
-    Frame* frame;
+    py_Frame* frame;
     int state;
 } Generator;
 
-void pk_newgenerator(py_Ref out, Frame* frame, py_TValue* begin, py_TValue* end);
+void pk_newgenerator(py_Ref out, py_Frame* frame, py_TValue* begin, py_TValue* end);
 
 void Generator__dtor(Generator* ud);
\ No newline at end of file
diff --git a/include/pocketpy/interpreter/vm.h b/include/pocketpy/interpreter/vm.h
index 836c0b38..6c3cfce5 100644
--- a/include/pocketpy/interpreter/vm.h
+++ b/include/pocketpy/interpreter/vm.h
@@ -24,7 +24,7 @@ typedef struct TraceInfo {
 } TraceInfo;
 
 typedef struct VM {
-    Frame* top_frame;
+    py_Frame* top_frame;
 
     ModuleDict modules;
     TypeList types;
@@ -57,7 +57,7 @@ typedef struct VM {
 void VM__ctor(VM* self);
 void VM__dtor(VM* self);
 
-void VM__push_frame(VM* self, Frame* frame);
+void VM__push_frame(VM* self, py_Frame* frame);
 void VM__pop_frame(VM* self);
 
 bool pk__parse_int_slice(py_Ref slice, int length, int* restrict start, int* restrict stop, int* restrict step);
@@ -108,7 +108,7 @@ bool pk_execdyn(CodeObject* co, py_Ref module, py_Ref globals, py_Ref locals);
 /// The stack remains unchanged.
 bool pk_stack_binaryop(VM* self, py_Name op, py_Name rop);
 
-void pk_print_stack(VM* self, Frame* frame, Bytecode byte);
+void pk_print_stack(VM* self, py_Frame* frame, Bytecode byte);
 
 // type registration
 void pk_object__register();
diff --git a/src/interpreter/ceval.c b/src/interpreter/ceval.c
index f11d9fd3..6ebc864d 100644
--- a/src/interpreter/ceval.c
+++ b/src/interpreter/ceval.c
@@ -69,7 +69,7 @@ static bool stack_format_object(VM* self, c11_sv spec);
             case RES_CALL: {                                                                       \
                 frame = self->top_frame;                                                           \
                 if(self->trace_info.tracefunc) {                                                   \
-                    self->trace_info.tracefunc((py_Frame*)frame, TRACE_EVENT_CALL);                \
+                    self->trace_info.tracefunc(frame, TRACE_EVENT_CALL);                           \
                 }                                                                                  \
                 goto __NEXT_FRAME;                                                                 \
             }                                                                                      \
@@ -91,10 +91,10 @@ static bool unpack_dict_to_buffer(py_Ref key, py_Ref val, void* ctx) {
 }
 
 FrameResult VM__run_top_frame(VM* self) {
-    Frame* frame = self->top_frame;
+    py_Frame* frame = self->top_frame;
     Bytecode* codes;
 
-    const Frame* base_frame = frame;
+    const py_Frame* base_frame = frame;
 
     while(true) {
         Bytecode byte;
@@ -112,7 +112,7 @@ FrameResult VM__run_top_frame(VM* self) {
                 if(prev_loc.src) PK_DECREF(prev_loc.src);
                 PK_INCREF(loc.src);
                 self->trace_info.prev_loc = loc;
-                self->trace_info.tracefunc((py_Frame*)frame, TRACE_EVENT_LINE);
+                self->trace_info.tracefunc(frame, TRACE_EVENT_LINE);
             }
         }
 
@@ -225,7 +225,7 @@ FrameResult VM__run_top_frame(VM* self) {
                 // locals
                 switch(frame->locals->type) {
                     case tp_locals: {
-                        Frame* noproxy = frame->locals->_ptr;
+                        py_Frame* noproxy = frame->locals->_ptr;
                         py_Ref slot = Frame__getlocal_noproxy(noproxy, name);
                         if(slot == NULL) break;
                         if(py_isnil(slot)) {
@@ -376,7 +376,7 @@ FrameResult VM__run_top_frame(VM* self) {
                 py_Name name = byte.arg;
                 switch(frame->locals->type) {
                     case tp_locals: {
-                        Frame* noproxy = frame->locals->_ptr;
+                        py_Frame* noproxy = frame->locals->_ptr;
                         py_Ref slot = Frame__getlocal_noproxy(noproxy, name);
                         if(slot == NULL) {
                             UnboundLocalError(name);
@@ -443,7 +443,7 @@ FrameResult VM__run_top_frame(VM* self) {
                 py_Name name = byte.arg;
                 switch(frame->locals->type) {
                     case tp_locals: {
-                        Frame* noproxy = frame->locals->_ptr;
+                        py_Frame* noproxy = frame->locals->_ptr;
                         py_Ref slot = Frame__getlocal_noproxy(noproxy, name);
                         if(slot == NULL || py_isnil(slot)) {
                             UnboundLocalError(name);
@@ -758,7 +758,7 @@ FrameResult VM__run_top_frame(VM* self) {
                     py_newnone(&self->last_retval);
                 }
                 if(self->trace_info.tracefunc) {
-                    self->trace_info.tracefunc((py_Frame*)frame, TRACE_EVENT_RETURN);
+                    self->trace_info.tracefunc(frame, TRACE_EVENT_RETURN);
                 }
                 VM__pop_frame(self);
                 if(frame == base_frame) {  // [ frameBase<- ]
diff --git a/src/interpreter/frame.c b/src/interpreter/frame.c
index 1ce45cb4..dbb98aa0 100644
--- a/src/interpreter/frame.c
+++ b/src/interpreter/frame.c
@@ -47,7 +47,7 @@ UnwindTarget* UnwindTarget__new(UnwindTarget* next, int iblock, int offset) {
 
 void UnwindTarget__delete(UnwindTarget* self) { PK_FREE(self); }
 
-Frame* Frame__new(const CodeObject* co,
+py_Frame* Frame__new(const CodeObject* co,
                   py_StackRef p0,
                   py_GlobalRef module,
                   py_Ref globals,
@@ -58,7 +58,7 @@ Frame* Frame__new(const CodeObject* co,
     if(is_locals_special) {
         assert(locals->type == tp_nil || locals->type == tp_locals || locals->type == tp_dict);
     }
-    Frame* self = FixedMemoryPool__alloc(&pk_current_vm->pool_frame);
+    py_Frame* self = FixedMemoryPool__alloc(&pk_current_vm->pool_frame);
     self->f_back = NULL;
     self->co = co;
     self->p0 = p0;
@@ -71,7 +71,7 @@ Frame* Frame__new(const CodeObject* co,
     return self;
 }
 
-void Frame__delete(Frame* self) {
+void Frame__delete(py_Frame* self) {
     while(self->uw_list) {
         UnwindTarget* p = self->uw_list;
         self->uw_list = p->next;
@@ -80,7 +80,7 @@ void Frame__delete(Frame* self) {
     FixedMemoryPool__dealloc(&pk_current_vm->pool_frame, self);
 }
 
-int Frame__prepare_jump_exception_handler(Frame* self, ValueStack* _s) {
+int Frame__prepare_jump_exception_handler(py_Frame* self, ValueStack* _s) {
     // try to find a parent try block
     int iblock = Frame__iblock(self);
     while(iblock >= 0) {
@@ -94,7 +94,7 @@ int Frame__prepare_jump_exception_handler(Frame* self, ValueStack* _s) {
     return c11__at(CodeBlock, &self->co->blocks, iblock)->end;
 }
 
-UnwindTarget* Frame__find_unwind_target(Frame* self, int iblock) {
+UnwindTarget* Frame__find_unwind_target(py_Frame* self, int iblock) {
     UnwindTarget* uw;
     for(uw = self->uw_list; uw; uw = uw->next) {
         if(uw->iblock == iblock) return uw;
@@ -102,7 +102,7 @@ UnwindTarget* Frame__find_unwind_target(Frame* self, int iblock) {
     return NULL;
 }
 
-void Frame__set_unwind_target(Frame* self, py_TValue* sp) {
+void Frame__set_unwind_target(py_Frame* self, py_TValue* sp) {
     int iblock = Frame__iblock(self);
     UnwindTarget* existing = Frame__find_unwind_target(self, iblock);
     if(existing) {
@@ -113,23 +113,23 @@ void Frame__set_unwind_target(Frame* self, py_TValue* sp) {
     }
 }
 
-void Frame__gc_mark(Frame* self) {
+void Frame__gc_mark(py_Frame* self) {
     pk__mark_value(self->globals);
     if(self->is_locals_special) pk__mark_value(self->locals);
     CodeObject__gc_mark(self->co);
 }
 
-int Frame__lineno(const Frame* self) {
+int Frame__lineno(const py_Frame* self) {
     int ip = self->ip;
     return c11__getitem(BytecodeEx, &self->co->codes_ex, ip).lineno;
 }
 
-int Frame__iblock(const Frame* self) {
+int Frame__iblock(const py_Frame* self) {
     int ip = self->ip;
     return c11__getitem(BytecodeEx, &self->co->codes_ex, ip).iblock;
 }
 
-int Frame__getglobal(Frame* self, py_Name name) {
+int Frame__getglobal(py_Frame* self, py_Name name) {
     if(self->globals->type == tp_module) {
         py_ItemRef item = py_getdict(self->globals, name);
         if(item != NULL) {
@@ -142,7 +142,7 @@ int Frame__getglobal(Frame* self, py_Name name) {
     }
 }
 
-bool Frame__setglobal(Frame* self, py_Name name, py_TValue* val) {
+bool Frame__setglobal(py_Frame* self, py_Name name, py_TValue* val) {
     if(self->globals->type == tp_module) {
         py_setdict(self->globals, name, val);
         return true;
@@ -151,7 +151,7 @@ bool Frame__setglobal(Frame* self, py_Name name, py_TValue* val) {
     }
 }
 
-int Frame__delglobal(Frame* self, py_Name name) {
+int Frame__delglobal(py_Frame* self, py_Name name) {
     if(self->globals->type == tp_module) {
         bool found = py_deldict(self->globals, name);
         return found ? 1 : 0;
@@ -160,14 +160,14 @@ int Frame__delglobal(Frame* self, py_Name name) {
     }
 }
 
-py_StackRef Frame__getlocal_noproxy(Frame* self, py_Name name) {
+py_StackRef Frame__getlocal_noproxy(py_Frame* self, py_Name name) {
     assert(!self->is_locals_special);
     int index = c11_smallmap_n2i__get(&self->co->varnames_inv, name, -1);
     if(index == -1) return NULL;
     return &self->locals[index];
 }
 
-py_Ref Frame__getclosure(Frame* self, py_Name name) {
+py_Ref Frame__getclosure(py_Frame* self, py_Name name) {
     if(self->is_locals_special) return NULL;
     assert(self->p0->type == tp_function);
     Function* ud = py_touserdata(self->p0);
@@ -175,7 +175,7 @@ py_Ref Frame__getclosure(Frame* self, py_Name name) {
     return NameDict__try_get(ud->closure, name);
 }
 
-SourceLocation Frame__source_location(Frame* self) {
+SourceLocation Frame__source_location(py_Frame* self) {
     SourceLocation loc;
     loc.lineno = Frame__lineno(self);
     loc.src = self->co->src;
diff --git a/src/interpreter/generator.c b/src/interpreter/generator.c
index 82eb4d48..5ca2cb6d 100644
--- a/src/interpreter/generator.c
+++ b/src/interpreter/generator.c
@@ -5,7 +5,7 @@
 #include "pocketpy/pocketpy.h"
 #include <stdbool.h>
 
-void pk_newgenerator(py_Ref out, Frame* frame, py_TValue* begin, py_TValue* end) {
+void pk_newgenerator(py_Ref out, py_Frame* frame, py_TValue* begin, py_TValue* end) {
     Generator* ud = py_newobject(out, tp_generator, 1, sizeof(Generator));
     ud->frame = frame;
     ud->state = 0;
diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index 7b11af2c..9f3f22d4 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -78,7 +78,7 @@ void VM__ctor(VM* self) {
     self->curr_function = NULL;
     memset(&self->trace_info, 0, sizeof(TraceInfo));
 
-    FixedMemoryPool__ctor(&self->pool_frame, sizeof(Frame), 32);
+    FixedMemoryPool__ctor(&self->pool_frame, sizeof(py_Frame), 32);
 
     ManagedHeap__ctor(&self->heap);
     ValueStack__ctor(&self->stack);
@@ -262,14 +262,14 @@ void VM__dtor(VM* self) {
     InternedNames__dtor(&self->names);
 }
 
-void VM__push_frame(VM* self, Frame* frame) {
+void VM__push_frame(VM* self, py_Frame* frame) {
     frame->f_back = self->top_frame;
     self->top_frame = frame;
 }
 
 void VM__pop_frame(VM* self) {
     assert(self->top_frame);
-    Frame* frame = self->top_frame;
+    py_Frame* frame = self->top_frame;
     // reset stack pointer
 
     self->stack.sp = frame->p0;
@@ -532,7 +532,7 @@ FrameResult VM__vectorcall(VM* self, uint16_t argc, uint16_t kwargc, bool opcall
                 // copy buffer back to stack
                 self->stack.sp = argv + co->nlocals;
                 memcpy(argv, self->vectorcall_buffer, co->nlocals * sizeof(py_TValue));
-                Frame* frame = Frame__new(co, p0, fn->module, fn->globals, argv, false);
+                py_Frame* frame = Frame__new(co, p0, fn->module, fn->globals, argv, false);
                 pk_newgenerator(py_retval(), frame, p0, self->stack.sp);
                 self->stack.sp = p0;  // reset the stack
                 return RES_RETURN;
@@ -717,7 +717,7 @@ void ManagedHeap__mark(ManagedHeap* self) {
         pk__mark_value(&ti->annotations);
     }
     // mark frame
-    for(Frame* frame = vm->top_frame; frame; frame = frame->f_back) {
+    for(py_Frame* frame = vm->top_frame; frame; frame = frame->f_back) {
         Frame__gc_mark(frame);
     }
     // mark vm's registers
@@ -733,7 +733,7 @@ void ManagedHeap__mark(ManagedHeap* self) {
     }
 }
 
-void pk_print_stack(VM* self, Frame* frame, Bytecode byte) {
+void pk_print_stack(VM* self, py_Frame* frame, Bytecode byte) {
     return;
     if(frame == NULL || py_isnil(&self->main)) return;
 
diff --git a/src/public/exec.c b/src/public/exec.c
index 0a69931c..0bf1d4e6 100644
--- a/src/public/exec.c
+++ b/src/public/exec.c
@@ -53,7 +53,7 @@ bool pk_exec(CodeObject* co, py_Ref module) {
     assert(module->type == tp_module);
 
     py_StackRef sp = vm->stack.sp;
-    Frame* frame = Frame__new(co, sp, module, module, py_NIL(), true);
+    py_Frame* frame = Frame__new(co, sp, module, module, py_NIL(), true);
     VM__push_frame(vm, frame);
     FrameResult res = VM__run_top_frame(vm);
     if(res == RES_ERROR) return false;
@@ -84,7 +84,7 @@ bool pk_execdyn(CodeObject* co, py_Ref module, py_Ref globals, py_Ref locals) {
         default: return TypeError("locals must be a dict object");
     }
 
-    Frame* frame = Frame__new(co, sp, module, globals, locals, true);
+    py_Frame* frame = Frame__new(co, sp, module, globals, locals, true);
     VM__push_frame(vm, frame);
     FrameResult res = VM__run_top_frame(vm);
     if(res == RES_ERROR) return false;
diff --git a/src/public/modules.c b/src/public/modules.c
index 35caf469..3f77d7db 100644
--- a/src/public/modules.c
+++ b/src/public/modules.c
@@ -493,7 +493,7 @@ static bool builtins_locals(int argc, py_Ref argv) {
 }
 
 void py_newglobals(py_Ref out) {
-    Frame* frame = pk_current_vm->top_frame;
+    py_Frame* frame = pk_current_vm->top_frame;
     if(!frame) {
         pk_mappingproxy__namedict(out, &pk_current_vm->main);
         return;
@@ -506,7 +506,7 @@ void py_newglobals(py_Ref out) {
 }
 
 void py_newlocals(py_Ref out) {
-    Frame* frame = pk_current_vm->top_frame;
+    py_Frame* frame = pk_current_vm->top_frame;
     if(!frame) {
         py_newdict(out);
         return;
@@ -524,7 +524,7 @@ void py_newlocals(py_Ref out) {
 }
 
 static void pk_push_special_locals() {
-    Frame* frame = pk_current_vm->top_frame;
+    py_Frame* frame = pk_current_vm->top_frame;
     if(!frame) {
         py_pushnil();
         return;
@@ -588,7 +588,7 @@ static bool _builtins_execdyn(const char* title, int argc, py_Ref argv, enum py_
         return TypeError("%s() expected 'str' or 'code', got '%t'", title, argv->type);
     }
 
-    Frame* frame = pk_current_vm->top_frame;
+    py_Frame* frame = pk_current_vm->top_frame;
     // [globals, locals, code]
     CodeObject* code = py_touserdata(py_peek(-1));
     if(code->src->is_dynamic) {
@@ -818,7 +818,7 @@ py_Type pk_nativefunc__register() {
 
 static bool super__new__(int argc, py_Ref argv) {
     py_Type class_arg = 0;
-    Frame* frame = pk_current_vm->top_frame;
+    py_Frame* frame = pk_current_vm->top_frame;
     py_Ref self_arg = NULL;
     if(argc == 1) {
         // super()
diff --git a/src/public/py_exception.c b/src/public/py_exception.c
index 9b3f04c4..38d8afc4 100644
--- a/src/public/py_exception.c
+++ b/src/public/py_exception.c
@@ -252,8 +252,8 @@ bool py_raise(py_Ref exc) {
     vm->curr_exception = *exc;
     vm->is_curr_exc_handled = false;
     if(vm->trace_info.tracefunc && !py_istype(exc, tp_StopIteration)) {
-        Frame* frame = vm->top_frame;
-        vm->trace_info.tracefunc((py_Frame*)frame, TRACE_EVENT_EXCEPTION);
+        py_Frame* frame = vm->top_frame;
+        vm->trace_info.tracefunc(frame, TRACE_EVENT_EXCEPTION);
     }
     return false;
 }
diff --git a/src/public/stack_ops.c b/src/public/stack_ops.c
index 2d4ddf84..ccf5972a 100644
--- a/src/public/stack_ops.c
+++ b/src/public/stack_ops.c
@@ -73,7 +73,7 @@ py_StackRef py_inspect_currentfunction(){
 }
 
 py_GlobalRef py_inspect_currentmodule(){
-    Frame* frame = pk_current_vm->top_frame;
+    py_Frame* frame = pk_current_vm->top_frame;
     if(!frame) return NULL;
     return frame->module;
 }