@@ -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
@@ -27,12 +27,12 @@
 OF_ASSUME_NONNULL_BEGIN
 
 #ifdef __cplusplus
 extern "C" {
 #endif
-extern const char *OFStrPTime(const char *buf, const char *fmt, struct tm *tm,
-    short *tz);
+extern const char *_Nullable OFStrPTime(const char *buffer, const char *format,
+    struct tm *tm, short *_Nullable tz);
 #ifdef __cplusplus
 }
 #endif
 
 OF_ASSUME_NONNULL_END