diff --git a/ironic/drivers/modules/redfish/boot.py b/ironic/drivers/modules/redfish/boot.py
index 49928acdf9..47b85cc251 100644
--- a/ironic/drivers/modules/redfish/boot.py
+++ b/ironic/drivers/modules/redfish/boot.py
@@ -278,7 +278,7 @@ def _has_vmedia_device(managers, boot_device, inserted=None):
         inserted status.
     :return: The device that could be found or False.
     """
-    if isinstance(boot_device, str):
+    if not isinstance(boot_device, list):
         boot_device = [boot_device]
 
     for dev in boot_device:
diff --git a/ironic/tests/unit/drivers/modules/drac/test_boot.py b/ironic/tests/unit/drivers/modules/drac/test_boot.py
index 66d01d8c3e..c6ab480e98 100644
--- a/ironic/tests/unit/drivers/modules/drac/test_boot.py
+++ b/ironic/tests/unit/drivers/modules/drac/test_boot.py
@@ -77,7 +77,7 @@ class DracBootTestCase(test_utils.BaseDracTest):
                 task, boot_devices.CDROM, persistent=True)
 
             mock_manager_oem.set_virtual_boot_device.assert_called_once_with(
-                'cd', persistent=True, system=mock_system)
+                sushy.VIRTUAL_MEDIA_CD, persistent=True, system=mock_system)
 
     def test__set_boot_device_cd(self, mock_get_system):
         mock_system = mock_get_system.return_value
@@ -90,7 +90,7 @@ class DracBootTestCase(test_utils.BaseDracTest):
             task.driver.boot._set_boot_device(task, boot_devices.CDROM)
 
             mock_manager_oem.set_virtual_boot_device.assert_called_once_with(
-                'cd', persistent=False, system=mock_system)
+                sushy.VIRTUAL_MEDIA_CD, persistent=False, system=mock_system)
 
     def test__set_boot_device_floppy(self, mock_get_system):
         mock_system = mock_get_system.return_value
@@ -103,7 +103,8 @@ class DracBootTestCase(test_utils.BaseDracTest):
             task.driver.boot._set_boot_device(task, boot_devices.FLOPPY)
 
             mock_manager_oem.set_virtual_boot_device.assert_called_once_with(
-                'floppy', persistent=False, system=mock_system)
+                sushy.VIRTUAL_MEDIA_FLOPPY, persistent=False,
+                system=mock_system)
 
     def test__set_boot_device_disk(self, mock_get_system):
         mock_system = mock_get_system.return_value