diff --git a/src/expr.cpp b/src/expr.cpp
index 791e3a8c..ebd88d4a 100644
--- a/src/expr.cpp
+++ b/src/expr.cpp
@@ -594,7 +594,12 @@ namespace pkpy{
             // vectorcall protocol
             for(auto& item: args) item->emit_(ctx);
             for(auto& item: kwargs){
-                uint16_t index = StrName(item.first.sv()).index;
+                i64 _val = StrName(item.first.sv()).index;
+                if(is_imm_int(_val)){
+                    ctx->emit_(OP_LOAD_INTEGER, (uint16_t)_val, line);
+                }else{
+                    ctx->emit_(OP_LOAD_CONST, ctx->add_const(py_var(ctx->vm, _val)), line);
+                }
                 ctx->emit_(OP_LOAD_INTEGER, index, line);
                 item.second->emit_(ctx);
             }
diff --git a/src/vm.cpp b/src/vm.cpp
index ad50a961..a9605ffb 100644
--- a/src/vm.cpp
+++ b/src/vm.cpp
@@ -837,7 +837,7 @@ 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]));
+        StrName key(_CAST(uint16_t, kwargs[j]));
         int index = decl->kw_to_index.try_get_likely_found(key);
         // if key is an explicit key, set as local variable
         if(index >= 0){