diff --git a/namedev.c b/namedev.c
index 391da7efca..d183a36329 100644
--- a/namedev.c
+++ b/namedev.c
@@ -527,6 +527,15 @@ static void apply_format(struct udevice *udev, unsigned char *string)
 				strcat(pos, udev->kernel_number);
 				dbg("substitute kernel number '%s'", udev->kernel_number);
 				break;
+			case 'D':
+				if (strlen(udev->kernel_number) == 0) {
+					strcat(pos, "disk");
+					break;
+				}
+				strcat(pos, "part");
+				strcat(pos, udev->kernel_number);
+				dbg("substitute kernel number '%s'", udev->kernel_number);
+				break;
 			case 'm':
 				sprintf(pos, "%u", udev->minor);
 				dbg("substitute minor number '%u'", udev->minor);