diff --git a/vm_args.c b/vm_args.c
index 79867293c8..49a80d1c9c 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -825,7 +825,7 @@ refine_sym_proc_call(RB_BLOCK_CALL_FUNC_ARGLIST(yielded_arg, callback_arg))
 }
 
 static void
-vm_caller_setup_arg_block(const rb_execution_context_t *th, rb_control_frame_t *reg_cfp,
+vm_caller_setup_arg_block(const rb_execution_context_t *ec, rb_control_frame_t *reg_cfp,
 			  struct rb_calling_info *calling, const struct rb_call_info *ci, rb_iseq_t *blockiseq, const int is_super)
 {
     if (ci->flag & VM_CALL_ARGS_BLOCKARG) {