diff --git a/2019/karns/Makefile b/2019/karns/Makefile
index 1542ad0aa..e7a66e012 100644
--- a/2019/karns/Makefile
+++ b/2019/karns/Makefile
@@ -173,6 +173,7 @@ clean:
 
 clobber: clean
 	${RM} -f ${TARGET} ${ALT_TARGET}
+	${RM} -f tbfs
 	@-if [ -e sandwich ]; then \
 	    ${RM} -f sandwich; \
 	    echo 'ate sandwich'; \