diff --git a/Makefile b/Makefile
index 2700622..b7fb22d 100644
--- a/Makefile
+++ b/Makefile
@@ -355,7 +355,7 @@ grade:
 	@echo $(MAKE) clean
 	@$(MAKE) clean || \
           (echo "'make clean' failed.  HINT: Do you have another running instance of xv6?" && exit 1)
-	python grade-lab-$(LAB) $(GRADEFLAGS)
+	./grade-lab-$(LAB) $(GRADEFLAGS)
 
 ##
 ## FOR submissions