diff --git a/ChangeLog b/ChangeLog
index 7a5c96dd2d..34af34d33b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-09-21  Ulrich Drepper  <drepper@redhat.com>
+
+	[BZ #12037]
+	* posix/unistd.h: Undo change of feature selection for ftruncate from
+	2010-01-11.
+
 2010-09-20  Ulrich Drepper  <drepper@redhat.com>
 
 	* sysdeps/x86_64/strcmp.S: Fix another typo in x86-64 strncasecmp limit
diff --git a/posix/unistd.h b/posix/unistd.h
index f8b84e3cb3..5ebcaf18ee 100644
--- a/posix/unistd.h
+++ b/posix/unistd.h
@@ -1020,6 +1020,9 @@ extern int truncate64 (__const char *__file, __off64_t __length)
      __THROW __nonnull ((1)) __wur;
 # endif
 
+#endif /* Use BSD || X/Open Unix || POSIX 2008.  */
+
+#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 
 /* Truncate the file FD is open on to LENGTH bytes.  */
 # ifndef __USE_FILE_OFFSET64