diff --git a/py/runtime.c b/py/runtime.c
index 9fc0b97..b08ae3d 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -64,6 +64,7 @@
             void *fun;
         } u_inline_asm;
     };
+    qstr *arg_names;
 } mp_code_t;
 
 STATIC uint next_unique_code_id;
@@ -242,7 +243,7 @@
     }
 }
 
-void rt_assign_byte_code(uint unique_code_id, byte *code, uint len, int n_args, int n_locals, int n_stack, uint scope_flags) {
+void rt_assign_byte_code(uint unique_code_id, byte *code, uint len, int n_args, int n_locals, int n_stack, uint scope_flags, qstr *arg_names) {
     alloc_unique_codes();
 
     assert(1 <= unique_code_id && unique_code_id < next_unique_code_id && unique_codes[unique_code_id].kind == MP_CODE_NONE);
@@ -252,6 +253,7 @@
     unique_codes[unique_code_id].n_state = n_locals + n_stack;
     unique_codes[unique_code_id].u_byte.code = code;
     unique_codes[unique_code_id].u_byte.len = len;
+    unique_codes[unique_code_id].arg_names = arg_names;
 
     //printf("byte code: %d bytes\n", len);
 
@@ -714,7 +716,7 @@
     mp_obj_t fun;
     switch (c->kind) {
         case MP_CODE_BYTE:
-            fun = mp_obj_new_fun_bc(c->scope_flags, c->n_args, def_args, c->n_state, c->u_byte.code);
+            fun = mp_obj_new_fun_bc(c->scope_flags, c->arg_names, c->n_args, def_args, c->n_state, c->u_byte.code);
             break;
         case MP_CODE_NATIVE:
             fun = rt_make_function_n(c->n_args, c->u_native.fun);