--- shadow-4.0.13/src/useradd.c.orig	2008-02-01 13:23:21.000000000 -0800
+++ shadow-4.0.13/src/useradd.c	2008-02-01 13:25:05.000000000 -0800
@@ -844,9 +844,12 @@ static void find_new_uid (void)
 	 * Start with some UID value if the user didn't provide us with
 	 * one already.
 	 */
-	if (!uflg)
+	if (!uflg) {
 		user_id = uid_min;
-
+	} else {
+		if (!getpwuid(user_id) && !getpwnam(user_name))
+			return;
+	}
 	/*
 	 * Search the entire password file, either looking for this
 	 * UID (if the user specified one with -u) or looking for the