diff --git a/init/init.c b/init/init.c
index a3e8d67..980150f 100644
--- a/init/init.c
+++ b/init/init.c
@@ -538,3 +538,7 @@
 	sleep(1);
     }
 }
+
+#if defined FOO
+    #error Ack!
+#endif