diff --git a/cgtests.mk b/cgtests.mk
index cd38396..e5027e9 100644
--- a/cgtests.mk
+++ b/cgtests.mk
@@ -5,10 +5,13 @@ tests = $(patsubst %.occ,%,$(wildcard cgtests/cgtest??.occ))
 
 all: $(tests)
 
+clean:
+	rm $(tests)
+
 checkout:
 	svn co http://projects.cs.kent.ac.uk/projects/kroc/svn/kroc/trunk/tests/cgtests
 
-%: %.occ tock
+%: %.occ
 	./tock -vk --backend=$(BACKEND) -o $@ $<
 
 run-all: $(addprefix run-,$(tests))