diff --git a/Scripts/extras/lab5.mk b/Scripts/extras/lab5.mk
index 38dba5e..fdd5451 100644
--- a/Scripts/extras/lab5.mk
+++ b/Scripts/extras/lab5.mk
@@ -51,7 +51,7 @@ gdb:
 
 grade:
 	$(Q)(test -f ${LABDIR}/.config && cp ${LABDIR}/.config ${LABDIR}/.config.bak) || :
-	$(Q)$(DOCKER_RUN) $(GRADER) -t $(TIMEOUT) -f $(LABDIR)/scores.json $(GRADER_V) -s $(SERIAL) make SERIAL=$(SERIAL) qemu-grade
+	$(Q)$(DOCKER_RUN) $(GRADER) -t $(TIMEOUT)
 	$(Q)(test -f ${LABDIR}/.config.bak && cp ${LABDIR}/.config.bak ${LABDIR}/.config && rm .config.bak) || :
 
 .PHONY: qemu qemu-gdb gdb defconfig build clean distclean grade all
diff --git a/Scripts/kernel.mk b/Scripts/kernel.mk
index 814f3fc..9732e9b 100644
--- a/Scripts/kernel.mk
+++ b/Scripts/kernel.mk
@@ -54,8 +54,10 @@ gdb:
 	$(Q)$(GDB) --nx -x $(SCRIPTS)/gdb/gdbinit
 
 grade:  
+	$(Q)$(MAKE) distclean &> /dev/null
 	$(Q)(test -f ${LABDIR}/.config && cp ${LABDIR}/.config ${LABDIR}/.config.bak) || :
-	$(Q)$(DOCKER_RUN) $(GRADER) -t $(TIMEOUT)
+	$(Q)$(MAKE) build
+	$(Q)$(DOCKER_RUN) $(GRADER) -t $(TIMEOUT) -f $(LABDIR)/scores.json $(GRADER_V) -s $(SERIAL) make SERIAL=$(SERIAL) qemu-grade
 	$(Q)(test -f ${LABDIR}/.config.bak && cp ${LABDIR}/.config.bak ${LABDIR}/.config && rm .config.bak) || :
 
 .PHONY: qemu qemu-gdb gdb defconfig build clean distclean grade all