diff --git a/2020/ferguson1/Makefile b/2020/ferguson1/Makefile
index ef21d7dd0..541adbf61 100644
--- a/2020/ferguson1/Makefile
+++ b/2020/ferguson1/Makefile
@@ -189,7 +189,7 @@ clean:
 	${RM} -f ${OBJ} ${ALT_OBJ}
 
 clobber: clean
-	${RM} -f ${TARGET} ${ALT_TARGET}
+	${RM} -f ${TARGET} ${ALT_TARGET} sandwich
 	${RM} -rf *.dSYM