diff --git a/test/Makefile b/test/Makefile
index 196d375..3c43726 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -88,6 +88,7 @@ clean:
 	rm -f simt
 	rm -f spit
 	rm -f wishbonet
+	rm -f *.json
 
 .PHONY: distclean
 distclean: clean