diff --git a/kernel/Makefile b/kernel/Makefile
index 1213feb..5e58276 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -143,6 +143,7 @@ $(kernel): kernel $(assembly_object_files) $(linker_script)
 		$(assembly_object_files) target/x86_64-blog_os/$(mode)/libucore.a
 
 kernel:
+	@mkdir build/$(arch) -p
 	@CC=$(cc) cargo xbuild $(build_args)
 
 # compile assembly files