diff --git a/ethernet.cc b/ethernet.cc
index fc4b8fe..4f0c08d 100644
--- a/ethernet.cc
+++ b/ethernet.cc
@@ -85,7 +85,8 @@
   } else if ((flags & IFF_LOWER_UP) == 0 && link_up_) {
     link_up_ = false;
     DestroyIPConfig();
-    manager()->DeregisterService(service_);
+    if (service_)
+      manager()->DeregisterService(service_);
     SelectService(NULL);
   }
 }