diff --git a/libnm-core/nm-setting-ethtool.c b/libnm-core/nm-setting-ethtool.c
index dc94406036..f1d6a8786c 100644
--- a/libnm-core/nm-setting-ethtool.c
+++ b/libnm-core/nm-setting-ethtool.c
@@ -254,7 +254,7 @@ const char **
 nm_setting_ethtool_get_optnames(NMSettingEthtool *setting, guint *out_length)
 {
     const char *const *names;
-    guint              len;
+    guint              len = 0;
 
     g_return_val_if_fail(NM_IS_SETTING_ETHTOOL(setting), NULL);