diff --git a/man7/feature_test_macros.7 b/man7/feature_test_macros.7
index 91ac5f150..c2bd74756 100644
--- a/man7/feature_test_macros.7
+++ b/man7/feature_test_macros.7
@@ -22,7 +22,7 @@
 .\" Formatted or processed versions of this manual, if unaccompanied by
 .\" the source, must acknowledge the copyright and authors of this work.
 .\"
-.TH FEATURE_TEST_MACROS 7 2011-09-17 "Linux" "Linux Programmer's Manual"
+.TH FEATURE_TEST_MACROS 7 2012-01-18 "Linux" "Linux Programmer's Manual"
 .SH NAME
 feature_test_macros \- feature test macros
 .SH SYNOPSIS
@@ -215,6 +215,10 @@ earlier glibc 2.1.x versions recognized an equivalent macro named
 Although the use of the latter macro is obsolete, glibc continues
 to recognize it for backward compatibility.
 .TP
+.B _ISOC11_SOURCE
+Exposes declarations consistent with the ISO C11 standard.
+This macro is recognized since glibc 2.16.
+.TP
 .B _LARGEFILE64_SOURCE
 Expose definitions for the alternative API specified by the
 LFS (Large File Summit) as a "transitional extension" to the