diff --git a/arch/risc-v/src/common/riscv_initialstate.c b/arch/risc-v/src/common/riscv_initialstate.c
index 014ad62280c3c..95183904ce841 100644
--- a/arch/risc-v/src/common/riscv_initialstate.c
+++ b/arch/risc-v/src/common/riscv_initialstate.c
@@ -97,7 +97,7 @@ void up_initial_state(struct tcb_s *tcb)
 
   if (tcb->pid == IDLE_PROCESS_ID)
     {
-      tcb->stack_alloc_ptr = (void *)g_cpux_idlestack(riscv_mhartid());
+      tcb->stack_alloc_ptr = (void *)g_cpux_idlestack(up_cpu_index());
       tcb->stack_base_ptr  = tcb->stack_alloc_ptr;
       tcb->adj_stack_size  = SMP_STACK_SIZE;