diff --git a/drivers/phy/phy-uclass.c b/drivers/phy/phy-uclass.c
index 629ef3aa3de..0baf314a347 100644
--- a/drivers/phy/phy-uclass.c
+++ b/drivers/phy/phy-uclass.c
@@ -211,6 +211,9 @@ int generic_phy_get_by_name(struct udevice *dev, const char *phy_name,
 
 	debug("%s(dev=%p, name=%s, phy=%p)\n", __func__, dev, phy_name, phy);
 
+	assert(phy);
+	phy->dev = NULL;
+
 	index = dev_read_stringlist_search(dev, "phy-names", phy_name);
 	if (index < 0) {
 		debug("dev_read_stringlist_search() failed: %d\n", index);
diff --git a/test/dm/phy.c b/test/dm/phy.c
index 4d4a083dd0f..09329b9f71f 100644
--- a/test/dm/phy.c
+++ b/test/dm/phy.c
@@ -29,7 +29,9 @@ static int dm_test_phy_base(struct unit_test_state *uts)
 	 * Get the same phy port in 2 different ways and compare.
 	 */
 	ut_assertok(generic_phy_get_by_name(parent, "phy1", &phy1_method1));
+	ut_assert(generic_phy_valid(&phy1_method1));
 	ut_assertok(generic_phy_get_by_index(parent, 0, &phy1_method2));
+	ut_assert(generic_phy_valid(&phy1_method2));
 	ut_asserteq(phy1_method1.id, phy1_method2.id);
 
 	/*
@@ -50,6 +52,10 @@ static int dm_test_phy_base(struct unit_test_state *uts)
 	ut_asserteq(-ENODEV, uclass_get_device(UCLASS_PHY, 4, &dev));
 	ut_asserteq(-ENODATA, generic_phy_get_by_name(parent,
 					"phy_not_existing", &phy1_method1));
+	ut_assert(!generic_phy_valid(&phy1_method1));
+	ut_asserteq(-ENOENT, generic_phy_get_by_index(parent, 3,
+						      &phy1_method2));
+	ut_assert(!generic_phy_valid(&phy1_method2));
 
 	return 0;
 }