diff --git a/include/pocketpy/cffi.h b/include/pocketpy/cffi.h
index f4adfb9f..1aade54c 100644
--- a/include/pocketpy/cffi.h
+++ b/include/pocketpy/cffi.h
@@ -8,9 +8,8 @@ namespace pkpy {
 
 #define PY_CLASS(T, mod, name)                  \
     static Type _type(VM* vm) {                 \
-        static const StrName __x0(#mod);        \
-        static const StrName __x1(#name);       \
-        return PK_OBJ_GET(Type, vm->_modules[__x0]->attr(__x1));               \
+        PK_LOCAL_STATIC const std::pair<StrName, StrName> _path(#mod, #name); \
+        return PK_OBJ_GET(Type, vm->_modules[_path.first]->attr()[_path.second]); \
     }                                                                       \
     static void _check_type(VM* vm, PyObject* val){                         \
         if(!vm->isinstance(val, T::_type(vm))){                             \
diff --git a/include/pocketpy/common.h b/include/pocketpy/common.h
index 5ce4cc74..a58b987b 100644
--- a/include/pocketpy/common.h
+++ b/include/pocketpy/common.h
@@ -59,6 +59,8 @@ struct GIL {
 
 #define PK_UNUSED(x) (void)(x)
 
+#define PK_LOCAL_STATIC static
+
 namespace pkpy{
 
 namespace std = ::std;
diff --git a/include/pocketpy/config.h b/include/pocketpy/config.h
index 3ad233c6..7c1b25c9 100644
--- a/include/pocketpy/config.h
+++ b/include/pocketpy/config.h
@@ -48,7 +48,7 @@
 // This is the maximum number of arguments in a function declaration
 // including positional arguments, keyword-only arguments, and varargs
 // (not recommended to change this)
-#define PK_MAX_CO_VARNAMES          255
+#define PK_MAX_CO_VARNAMES          32
 
 namespace pkpy{
     // Hash table load factor (smaller ones mean less collision but more memory)
diff --git a/include/pocketpy/linalg.h b/include/pocketpy/linalg.h
index fc079b6a..48125d93 100644
--- a/include/pocketpy/linalg.h
+++ b/include/pocketpy/linalg.h
@@ -102,18 +102,15 @@ struct Mat3x3{
     void set_identity(){ set_zeros(); _11 = _22 = _33 = 1.0f; }
 
     static Mat3x3 zeros(){
-        static Mat3x3 ret(0, 0, 0, 0, 0, 0, 0, 0, 0);
-        return ret;
+        return Mat3x3(0, 0, 0, 0, 0, 0, 0, 0, 0);
     }
 
     static Mat3x3 ones(){
-        static Mat3x3 ret(1, 1, 1, 1, 1, 1, 1, 1, 1);
-        return ret;
+        return Mat3x3(1, 1, 1, 1, 1, 1, 1, 1, 1);
     }
 
     static Mat3x3 identity(){
-        static Mat3x3 ret(1, 0, 0, 0, 1, 0, 0, 0, 1);
-        return ret;
+        return Mat3x3(1, 0, 0, 0, 1, 0, 0, 0, 1);
     }
 
     Mat3x3 operator+(const Mat3x3& other) const{ 
diff --git a/include/pocketpy/obj.h b/include/pocketpy/obj.h
index db2f21ed..094da466 100644
--- a/include/pocketpy/obj.h
+++ b/include/pocketpy/obj.h
@@ -165,7 +165,6 @@ Str obj_type_name(VM* vm, Type type);
 #if PK_DEBUG_NO_BUILTINS
 #define OBJ_NAME(obj) Str("<?>")
 #else
-DEF_SNAME(__name__);
 #define OBJ_NAME(obj) PK_OBJ_GET(Str, vm->getattr(obj, __name__))
 #endif
 
diff --git a/include/pocketpy/pocketpy.h b/include/pocketpy/pocketpy.h
index 14ac1464..62038860 100644
--- a/include/pocketpy/pocketpy.h
+++ b/include/pocketpy/pocketpy.h
@@ -59,7 +59,7 @@ struct PyREPL{
         vm->bind_method<1>(type, "input", [](VM* vm, ArgsView args){
             PyREPL& self = _CAST(PyREPL&, args[0]);
             const Str& s = CAST(Str&, args[1]);
-            static std::stringstream ss_out;
+            PK_LOCAL_STATIC std::stringstream ss_out;
             ss_out.str("");
             TempOut _(vm, [](VM* vm, const Str& s){ ss_out << s; });
             bool ok = self.repl->input(s.str());
diff --git a/include/pocketpy/str.h b/include/pocketpy/str.h
index 430e0582..c8f7b316 100644
--- a/include/pocketpy/str.h
+++ b/include/pocketpy/str.h
@@ -174,6 +174,19 @@ const StrName __getitem__ = StrName::get("__getitem__");
 const StrName __setitem__ = StrName::get("__setitem__");
 const StrName __delitem__ = StrName::get("__delitem__");
 
+// specials
+const StrName __new__ = StrName::get("__new__");
+const StrName __init__ = StrName::get("__init__");
+const StrName __call__ = StrName::get("__call__");
+const StrName __divmod__ = StrName::get("__divmod__");
+const StrName __enter__ = StrName::get("__enter__");
+const StrName __exit__ = StrName::get("__exit__");
+const StrName __name__ = StrName::get("__name__");
+
+const StrName pk_id_add = StrName::get("add");
+const StrName pk_id_set = StrName::get("set");
+const StrName pk_id_eval = StrName::get("eval");
+
 #define DEF_SNAME(name) const static StrName name(#name)
 
 } // namespace pkpy
\ No newline at end of file
diff --git a/src/ceval.cpp b/src/ceval.cpp
index 9fce2eb3..9c2a1633 100644
--- a/src/ceval.cpp
+++ b/src/ceval.cpp
@@ -3,11 +3,6 @@
 namespace pkpy{
 
 PyObject* VM::_run_top_frame(){
-    DEF_SNAME(add);
-    DEF_SNAME(set);
-    DEF_SNAME(__enter__);
-    DEF_SNAME(__exit__);
-
     FrameId frame = top_frame();
     const int base_id = frame.index;
     bool need_raise = false;
@@ -242,7 +237,7 @@ __NEXT_STEP:;
         DISPATCH();
     /*****************************************/
     TARGET(BUILD_LONG) {
-        const static StrName m_long("long");
+        PK_LOCAL_STATIC const StrName m_long("long");
         _0 = builtins->attr().try_get(m_long);
         if(_0 == nullptr) AttributeError(builtins, m_long);
         TOP() = call(_0, TOP());
@@ -275,7 +270,7 @@ __NEXT_STEP:;
         DISPATCH();
     TARGET(BUILD_SET)
         _0 = VAR(STACK_VIEW(byte.arg).to_list());
-        _0 = call(builtins->attr(set), _0);
+        _0 = call(builtins->attr(pk_id_set), _0);
         STACK_SHRINK(byte.arg);
         PUSH(_0);
         DISPATCH();
@@ -323,7 +318,7 @@ __NEXT_STEP:;
         _unpack_as_list(STACK_VIEW(byte.arg), list);
         STACK_SHRINK(byte.arg);
         _0 = VAR(std::move(list));
-        _0 = call(builtins->attr(set), _0);
+        _0 = call(builtins->attr(pk_id_set), _0);
         PUSH(_0);
     } DISPATCH();
     /*****************************************/
@@ -499,11 +494,10 @@ __NEXT_STEP:;
         frame->jump_abs_break(index);
     } DISPATCH();
     /*****************************************/
-    TARGET(EVAL){
-        DEF_SNAME(eval);
-        _0 = builtins->attr(eval);
+    TARGET(EVAL)
+        _0 = builtins->attr(pk_id_eval);
         TOP() = call(_0, TOP());
-    } DISPATCH();
+        DISPATCH();
     TARGET(CALL)
         _0 = vectorcall(
             byte.arg & 0xFFFF,          // ARGC
@@ -565,7 +559,7 @@ __NEXT_STEP:;
     } DISPATCH();
     TARGET(SET_ADD)
         _0 = POPX();
-        call_method(SECOND(), add, _0);
+        call_method(SECOND(), pk_id_add, _0);
         DISPATCH();
     /*****************************************/
     TARGET(UNARY_NEGATIVE)
diff --git a/src/expr.cpp b/src/expr.cpp
index 301a1658..fe514f1c 100644
--- a/src/expr.cpp
+++ b/src/expr.cpp
@@ -365,7 +365,7 @@ namespace pkpy{
 
     void FStringExpr::emit(CodeEmitContext* ctx){
         VM* vm = ctx->vm;
-        static const std::regex pattern(R"(\{(.*?)\})");
+        PK_LOCAL_STATIC const std::regex pattern(R"(\{(.*?)\})");
         std::cregex_iterator begin(src.begin(), src.end(), pattern);
         std::cregex_iterator end;
         int size = 0;
diff --git a/src/io.cpp b/src/io.cpp
index c6a080d4..63329f8a 100644
--- a/src/io.cpp
+++ b/src/io.cpp
@@ -89,8 +89,8 @@ void add_module_io(VM* vm){
     PyObject* mod = vm->new_module("io");
     FileIO::register_class(vm, mod);
     vm->bind_builtin_func<2>("open", [](VM* vm, ArgsView args){
-        static StrName m_io("io");
-        static StrName m_FileIO("FileIO");
+        PK_LOCAL_STATIC StrName m_io("io");
+        PK_LOCAL_STATIC StrName m_FileIO("FileIO");
         return vm->call(vm->_modules[m_io]->attr(m_FileIO), args[0], args[1]);
     });
 #endif
diff --git a/src/lexer.cpp b/src/lexer.cpp
index 75a88601..78a7f5c9 100644
--- a/src/lexer.cpp
+++ b/src/lexer.cpp
@@ -260,7 +260,7 @@ static bool is_unicode_Lo_char(uint32_t c) {
     }
 
     void Lexer::eat_number() {
-        static const std::regex pattern("^(0x)?[0-9a-fA-F]+(\\.[0-9]+)?(L)?");
+        PK_LOCAL_STATIC const std::regex pattern("^(0x)?[0-9a-fA-F]+(\\.[0-9]+)?(L)?");
         std::smatch m;
 
         const char* i = token_start;
diff --git a/src/pocketpy.cpp b/src/pocketpy.cpp
index 91214b5f..e4055904 100644
--- a/src/pocketpy.cpp
+++ b/src/pocketpy.cpp
@@ -132,7 +132,7 @@ void init_builtins(VM* _vm) {
             vm->ValueError("pow(): rhs should be positive");
         }
 
-        static const auto _mul = [](i64 a, i64 b, i64 c){
+        PK_LOCAL_STATIC const auto _mul = [](i64 a, i64 b, i64 c){
             if(c < 16384) return (a%c) * (b%c) % c;
             i64 res = 0;
             while(b > 0){
@@ -192,7 +192,6 @@ void init_builtins(VM* _vm) {
             auto res = std::div(lhs, rhs);
             return VAR(Tuple({VAR(res.quot), VAR(res.rem)}));
         }else{
-            DEF_SNAME(__divmod__);
             return vm->call_method(args[0], __divmod__, args[1]);
         }
     });
@@ -853,7 +852,7 @@ void init_builtins(VM* _vm) {
         return VAR(val ? "true" : "false");
     });
 
-    const static auto f_bool_add = [](VM* vm, PyObject* lhs, PyObject* rhs) -> PyObject* {
+    const PK_LOCAL_STATIC auto f_bool_add = [](VM* vm, PyObject* lhs, PyObject* rhs) -> PyObject* {
         int x = (int)_CAST(bool, lhs);
         if(is_int(rhs)) return VAR(x + _CAST(int, rhs));
         if(rhs == vm->True) return VAR(x + 1);
@@ -861,7 +860,7 @@ void init_builtins(VM* _vm) {
         return vm->NotImplemented;
     };
 
-    const static auto f_bool_mul = [](VM* vm, PyObject* lhs, PyObject* rhs) -> PyObject* {
+    const PK_LOCAL_STATIC auto f_bool_mul = [](VM* vm, PyObject* lhs, PyObject* rhs) -> PyObject* {
         int x = (int)_CAST(bool, lhs);
         if(is_int(rhs)) return VAR(x * _CAST(int, rhs));
         if(rhs == vm->True) return VAR(x);
diff --git a/src/vm.cpp b/src/vm.cpp
index 136ab7c9..0803e647 100644
--- a/src/vm.cpp
+++ b/src/vm.cpp
@@ -743,7 +743,7 @@ PyObject* VM::vectorcall(int ARGC, int KWARGC, bool op_call){
     ArgsView args(p1 - ARGC - int(method_call), p1);
     ArgsView kwargs(p1, s_data._sp);
 
-    static PK_THREAD_LOCAL PyObject* buffer[PK_MAX_CO_VARNAMES];
+    PyObject* buffer[PK_MAX_CO_VARNAMES];
 
     if(is_non_tagged_type(callable, tp_native_func)){
         const auto& f = PK_OBJ_GET(NativeFunc, callable);
@@ -796,8 +796,6 @@ PyObject* VM::vectorcall(int ARGC, int KWARGC, bool op_call){
     if(is_non_tagged_type(callable, tp_type)){
         if(method_call) FATAL_ERROR();
         // [type, NULL, args..., kwargs...]
-
-        DEF_SNAME(__new__);
         PyObject* new_f = find_name_in_mro(callable, __new__);
         PyObject* obj;
 #if PK_DEBUG_EXTRA_CHECK
@@ -819,7 +817,6 @@ PyObject* VM::vectorcall(int ARGC, int KWARGC, bool op_call){
 
         // __init__
         PyObject* self;
-        DEF_SNAME(__init__);
         callable = get_unbound_method(obj, __init__, &self, false);
         if (self != PY_NULL) {
             // replace `NULL` with `self`
@@ -838,7 +835,6 @@ PyObject* VM::vectorcall(int ARGC, int KWARGC, bool op_call){
 
     // handle `__call__` overload
     PyObject* self;
-    DEF_SNAME(__call__);
     PyObject* call_f = get_unbound_method(callable, __call__, &self, false);
     if(self != PY_NULL){
         p1[-(ARGC + 2)] = call_f;