diff --git a/doc/go1.5.html b/doc/go1.5.html
index 7d0e6e357fa..87dbfde33b7 100644
--- a/doc/go1.5.html
+++ b/doc/go1.5.html
@@ -242,6 +242,11 @@ On NaCl, Go 1.5 requires SDK version pepper-39 or above because it now uses the
 <code>get_random_bytes</code> system call.
 </p>
 
+<p>
+On Darwin, the use of the system X.509 certificate interface can be disabled
+with the <code>ios</code> build tag.
+</p>
+
 <h2 id="tools">Tools</h2>
 
 <h3 id="translate">Translating</h3>