diff --git a/include/pocketpy/codeobject.h b/include/pocketpy/codeobject.h
index 7aed2355..9ad1df12 100644
--- a/include/pocketpy/codeobject.h
+++ b/include/pocketpy/codeobject.h
@@ -123,12 +123,13 @@ struct CodeObject {
 
 struct FuncDecl {
     struct KwArg {
-        int key;                // index in co->varnames
+        int index;              // index in co->varnames
+        StrName key;            // name of this argument
         PyObject* value;        // default value
     };
     CodeObject_ code;           // code object of this function
-    pod_vector<int> args;       // indices in co->varnames
-    pod_vector<KwArg> kwargs;   // indices in co->varnames
+    std::vector<int> args;      // indices in co->varnames
+    std::vector<KwArg> kwargs;  // indices in co->varnames
     int starred_arg = -1;       // index in co->varnames, -1 if no *arg
     int starred_kwarg = -1;     // index in co->varnames, -1 if no **kwarg
     bool nested = false;        // whether this function is nested
@@ -136,6 +137,11 @@ struct FuncDecl {
     Str signature;              // signature of this function
     Str docstring;              // docstring of this function
     bool is_simple;
+
+    int keyword_to_index(StrName key) const{
+        for(const KwArg& item: kwargs) if(item.key == key) return item.index;
+        return -1;
+    }
     void _gc_mark() const;
 };
 
diff --git a/src/compiler.cpp b/src/compiler.cpp
index 4a2ccc2d..36d94219 100644
--- a/src/compiler.cpp
+++ b/src/compiler.cpp
@@ -1007,7 +1007,7 @@ __EAT_DOTS_END:
                 }
             }
             for(auto& kv: decl->kwargs){
-                if(decl->code->varnames[kv.key] == name){
+                if(decl->code->varnames[kv.index] == name){
                     SyntaxError("duplicate argument name");
                 }
             }
@@ -1037,7 +1037,7 @@ __EAT_DOTS_END:
                     if(value == nullptr){
                         SyntaxError(Str("default argument must be a literal"));
                     }
-                    decl->kwargs.push_back(FuncDecl::KwArg{index, value});
+                    decl->kwargs.push_back(FuncDecl::KwArg{index, name, value});
                 } break;
                 case 3:
                     decl->starred_kwarg = index;
diff --git a/src/vm.cpp b/src/vm.cpp
index 1036222e..595c3a5c 100644
--- a/src/vm.cpp
+++ b/src/vm.cpp
@@ -580,7 +580,7 @@ PyObject* VM::new_module(Str name, Str package) {
 }
 
 static std::string _opcode_argstr(VM* vm, Bytecode byte, const CodeObject* co){
-    std::string argStr = byte.arg == BC_NOARG ? "" : std::to_string(byte.arg);
+    std::string argStr = std::to_string(byte.arg);
     switch(byte.op){
         case OP_LOAD_CONST: case OP_FORMAT_STRING: case OP_IMPORT_PATH:
             if(vm != nullptr){
@@ -818,7 +818,7 @@ void VM::_prepare_py_call(PyObject** buffer, ArgsView args, ArgsView kwargs, con
     // set extra varnames to PY_NULL
     for(int j=i; j<co_nlocals; j++) buffer[j] = PY_NULL;
     // prepare kwdefaults
-    for(auto& kv: decl->kwargs) buffer[kv.key] = kv.value;
+    for(auto& kv: decl->kwargs) buffer[kv.index] = kv.value;
     
     // handle *args
     if(decl->starred_arg != -1){
@@ -829,7 +829,7 @@ void VM::_prepare_py_call(PyObject** buffer, ArgsView args, ArgsView kwargs, con
         // kwdefaults override
         for(auto& kv: decl->kwargs){
             if(i >= args.size()) break;
-            buffer[kv.key] = args[i++];
+            buffer[kv.index] = args[i++];
         }
         if(i < args.size()) TypeError(fmt("too many arguments", " (", decl->code->name, ')'));
     }
@@ -844,16 +844,18 @@ void VM::_prepare_py_call(PyObject** buffer, ArgsView args, ArgsView kwargs, con
 
     for(int j=0; j<kwargs.size(); j+=2){
         StrName key(CAST(int, kwargs[j]));
-        int index = co->varnames_inv.try_get_likely_found(key);
-        if(index < 0){
+        int index = decl->keyword_to_index(key);
+        // if key is an explicit key, set as local variable
+        if(index != -1){
+            buffer[index] = kwargs[j+1];
+        }else{
+            // otherwise, set as **kwargs if possible
             if(vkwargs == nullptr){
                 TypeError(fmt(key.escape(), " is an invalid keyword argument for ", co->name, "()"));
             }else{
                 Dict& dict = _CAST(Dict&, vkwargs);
                 dict.set(VAR(key.sv()), kwargs[j+1]);
             }
-        }else{
-            buffer[index] = kwargs[j+1];
         }
     }
 }
diff --git a/tests/99_bugs.py b/tests/99_bugs.py
index 07f7949a..b6563d92 100644
--- a/tests/99_bugs.py
+++ b/tests/99_bugs.py
@@ -78,4 +78,26 @@ def f():
     ++g
 
 f(); f()
-assert g == 3
\ No newline at end of file
+assert g == 3
+
+
+def f(**kw):
+    x = 1
+    y = 2
+    return kw, x, y
+assert f(x=4, z=1) == ({'x': 4, 'z': 1}, 1, 2)
+
+def g(**kw):
+    x, y = 1, 2
+    return kw
+
+ret = g(
+    a=1, b=2, c=3, d=4, e=5, f=6, g=7, h=8, i=9,
+    j=10, k=11, l=12, m=13, n=14, o=15, p=16, q=17,
+    r=18, s=19, t=20, u=21, v=22, w=23, x=24, y=25,
+    z=26
+)
+assert ret == {chr(i+97): i+1 for i in range(26)}
+
+assert g(**ret) == ret
+assert g(**g(**ret)) == ret