diff --git a/shared/nm-libnm-core-intern/nm-ethtool-utils.c b/shared/nm-libnm-core-intern/nm-ethtool-utils.c
index f080b5c173..ace47680f5 100644
--- a/shared/nm-libnm-core-intern/nm-ethtool-utils.c
+++ b/shared/nm-libnm-core-intern/nm-ethtool-utils.c
@@ -196,7 +196,8 @@ nm_ethtool_data_get_by_optname (const char *optname)
 {
 	gssize idx;
 
-	nm_assert (optname);
+	if (!optname)
+		return NULL;
 
 	_ASSERT_data ();