diff --git a/src/uraid.c b/src/uraid.c
index e0a333a..3eb8872 100644
--- a/src/uraid.c
+++ b/src/uraid.c
@@ -979,7 +979,7 @@ int device_after_raid() {
 
 
 #ifdef MAIKO_ENABLE_ETHERNET
-  FD_SET(ether_fd, &LispReadFds);
+  if (ether_fd > 0) FD_SET(ether_fd, &LispReadFds);
 #endif /* MAIKO_ENABLE_ETHERNET */
 
 #ifdef XWINDOW