diff --git a/libnm-core/nm-keyfile-reader.c b/libnm-core/nm-keyfile-reader.c
index 5934c833ba..0ac417cdb4 100644
--- a/libnm-core/nm-keyfile-reader.c
+++ b/libnm-core/nm-keyfile-reader.c
@@ -185,7 +185,8 @@ build_route (KeyfileReaderInfo *info,
              const char *gateway_str, const char *metric_str)
 {
 	NMIPRoute *route;
-	guint32 metric = 0;
+	guint32 u32;
+	gint64 metric = -1;
 	GError *error = NULL;
 
 	g_return_val_if_fail (plen, NULL);
@@ -204,9 +205,10 @@ build_route (KeyfileReaderInfo *info,
 			 **/
 			if (   family == AF_INET6
 			    && !metric_str
-			    && get_one_int (NULL, NULL, gateway_str, G_MAXUINT32, &metric))
+			    && get_one_int (NULL, NULL, gateway_str, G_MAXUINT32, &u32)) {
+				metric = u32;
 				gateway_str = NULL;
-			else {
+			} else {
 				if (!info->error) {
 					handle_warn (info, property_name, NM_KEYFILE_WARN_SEVERITY_WARN,
 					             _("ignoring invalid gateway '%s' for %s route"),
@@ -218,14 +220,15 @@ build_route (KeyfileReaderInfo *info,
 	} else
 		gateway_str = NULL;
 
-	/* parse metric, default to 0 */
+	/* parse metric, default to -1 */
 	if (metric_str) {
-		if (!get_one_int (info, property_name, metric_str, G_MAXUINT32, &metric))
+		if (!get_one_int (info, property_name, metric_str, G_MAXUINT32, &u32))
 			return NULL;
+		metric = u32;
 	}
 
 	route = nm_ip_route_new (family, dest_str, plen, gateway_str,
-	                         metric ? (gint64) metric : -1,
+	                         metric,
 	                         &error);
 	if (!route) {
 		handle_warn (info, property_name, NM_KEYFILE_WARN_SEVERITY_WARN,
diff --git a/libnm-core/nm-keyfile-writer.c b/libnm-core/nm-keyfile-writer.c
index 87c87fcc95..eeeb3b4650 100644
--- a/libnm-core/nm-keyfile-writer.c
+++ b/libnm-core/nm-keyfile-writer.c
@@ -137,7 +137,7 @@ write_ip_values (GKeyFile *file,
 	GString *output;
 	int family, i;
 	const char *addr, *gw;
-	guint32 plen, metric;
+	guint32 plen;
 	char key_name[64], *key_name_idx;
 
 	if (!array->len)
@@ -150,25 +150,27 @@ write_ip_values (GKeyFile *file,
 
 	output = g_string_sized_new (2*INET_ADDRSTRLEN + 10);
 	for (i = 0; i < array->len; i++) {
+		gint64 metric = -1;
+
 		if (is_route) {
 			NMIPRoute *route = array->pdata[i];
 
 			addr = nm_ip_route_get_dest (route);
 			plen = nm_ip_route_get_prefix (route);
 			gw = nm_ip_route_get_next_hop (route);
-			metric = MAX (0, nm_ip_route_get_metric (route));
+			metric = nm_ip_route_get_metric (route);
 		} else {
 			NMIPAddress *address = array->pdata[i];
 
 			addr = nm_ip_address_get_address (address);
 			plen = nm_ip_address_get_prefix (address);
 			gw = i == 0 ? gateway : NULL;
-			metric = 0;
 		}
 
 		g_string_set_size (output, 0);
 		g_string_append_printf (output, "%s/%u", addr, plen);
-		if (metric || gw) {
+		if (   metric != -1
+		    || gw) {
 			/* Older versions of the plugin do not support the form
 			 * "a.b.c.d/plen,,metric", so, we always have to write the
 			 * gateway, even if there isn't one.
@@ -182,7 +184,7 @@ write_ip_values (GKeyFile *file,
 			}
 
 			g_string_append_printf (output, ",%s", gw);
-			if (metric)
+			if (is_route && metric != -1)
 				g_string_append_printf (output, ",%lu", (unsigned long) metric);
 		}
 
diff --git a/src/settings/plugins/keyfile/tests/test-keyfile.c b/src/settings/plugins/keyfile/tests/test-keyfile.c
index d9da53173a..2584a72290 100644
--- a/src/settings/plugins/keyfile/tests/test-keyfile.c
+++ b/src/settings/plugins/keyfile/tests/test-keyfile.c
@@ -312,11 +312,11 @@ test_read_valid_wired_connection (void)
 	check_ip_route (s_ip4, 3, "1.1.1.3", 13, NULL, -1);
 	check_ip_route (s_ip4, 4, "1.1.1.4", 14, "2.2.2.4", -1);
 	check_ip_route (s_ip4, 5, "1.1.1.5", 15, "2.2.2.5", -1);
-	check_ip_route (s_ip4, 6, "1.1.1.6", 16, "2.2.2.6", -1);
+	check_ip_route (s_ip4, 6, "1.1.1.6", 16, "2.2.2.6", 0);
 	check_ip_route (s_ip4, 7, "1.1.1.7", 17, NULL, -1);
 	check_ip_route (s_ip4, 8, "1.1.1.8", 18, NULL, -1);
-	check_ip_route (s_ip4, 9, "1.1.1.9", 19, NULL, -1);
-	check_ip_route (s_ip4, 10, "1.1.1.10", 20, NULL, -1);
+	check_ip_route (s_ip4, 9, "1.1.1.9", 19, NULL, 0);
+	check_ip_route (s_ip4, 10, "1.1.1.10", 20, NULL, 0);
 	check_ip_route (s_ip4, 11, "1.1.1.11", 21, NULL, 21);
 
 	/* Route attributes */