diff --git a/kernel/Makefile b/kernel/Makefile
index e344ad1..471585c 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -89,6 +89,7 @@ all: $(kernel)
 
 clean:
 	@cargo clean
+	@rm -rf ../riscv-pk/build
 
 doc:
 	@cargo rustdoc -- --document-private-items