diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 57f4dc1e57..dde4efb933 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -507,11 +507,7 @@
 				reg = <1>;
 				label = "lan1";
 				phy-mode = "rgmii-txid";
-
-				fixed-link {
-					speed = <100>;
-					full-duplex;
-				};
+				fixed-link = <0 1 100 0 0>;
 			};
 
 			port@2 {
diff --git a/test/dm/of_extra.c b/test/dm/of_extra.c
index b19cd3787d..ac2d886892 100644
--- a/test/dm/of_extra.c
+++ b/test/dm/of_extra.c
@@ -36,3 +36,21 @@ static int dm_test_ofnode_read_fmap_entry(struct unit_test_state *uts)
 	return 0;
 }
 DM_TEST(dm_test_ofnode_read_fmap_entry, 0);
+
+static int dm_test_ofnode_phy_is_fixed_link(struct unit_test_state *uts)
+{
+	ofnode eth_node, phy_node, node;
+
+	eth_node = ofnode_path("/dsa-test/ports/port@0");
+	ut_assert(ofnode_phy_is_fixed_link(eth_node, &phy_node));
+	node = ofnode_path("/dsa-test/ports/port@0/fixed-link");
+	ut_asserteq_mem(&phy_node, &node, sizeof(ofnode));
+
+	eth_node = ofnode_path("/dsa-test/ports/port@1");
+	ut_assert(ofnode_phy_is_fixed_link(eth_node, &phy_node));
+	node = eth_node;
+	ut_asserteq_mem(&phy_node, &node, sizeof(ofnode));
+
+	return 0;
+}
+DM_TEST(dm_test_ofnode_phy_is_fixed_link, 0);