diff --git a/src/ether.c b/src/ether.c
index a3e452f..b5b093c 100644
--- a/src/ether.c
+++ b/src/ether.c
@@ -58,7 +58,7 @@
 #include <sys/mbuf.h>
 #endif
 #include <nlist.h>
-#endif
+#endif /* MAIKO_ENABLE_ETHERNET */
 
 #include "commondefs.h"
 #include "lispemul.h"