diff --git a/include/linux/com20020.h b/include/linux/com20020.h
index 350afa773f8f..5dcfb944b6ce 100644
--- a/include/linux/com20020.h
+++ b/include/linux/com20020.h
@@ -29,7 +29,7 @@
 
 int com20020_check(struct net_device *dev);
 int com20020_found(struct net_device *dev, int shared);
-const struct net_device_ops com20020_netdev_ops;
+extern const struct net_device_ops com20020_netdev_ops;
 
 /* The number of low I/O ports used by the card. */
 #define ARCNET_TOTAL_SIZE 8