diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index f68d34d93a..ebf31aa244 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -46,6 +46,8 @@ ec_stack_overflow(rb_execution_context_t *ec, int setup)
     EC_JUMP_TAG(ec, TAG_RAISE);
 }
 
+NORETURN(static void vm_stackoverflow(void));
+
 static void
 vm_stackoverflow(void)
 {