@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2008-2021 Jonathan Schleifer <js@nil.im>
+ * Copyright (c) 2008-2022 Jonathan Schleifer <js@nil.im>
  *
  * All rights reserved.
  *
  * This file is part of ObjFW. It may be distributed under the terms of the
  * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
@@ -29,11 +29,11 @@
  *
  * @brief An exception indicating that starting a thread failed.
  */
 @interface OFThreadStartFailedException: OFException
 {
-	OFThread *_thread;
+	OFThread *_Nullable _thread;
 	int _errNo;
 }
 
 /**
  * @brief The thread which could not be started.
@@ -52,10 +52,12 @@
  * @param errNo The errno of the error that occurred
  * @return A new, autoreleased thread start failed exception
  */
 + (instancetype)exceptionWithThread: (nullable OFThread *)thread
 			      errNo: (int)errNo;
+
++ (instancetype)exception OF_UNAVAILABLE;
 
 /**
  * @brief Initializes an already allocated thread start failed exception.
  *
  * @param thread The thread which could not be started