diff --git a/errata.html b/errata.html
index 6548863..bb40aa1 100644
--- a/errata.html
+++ b/errata.html
@@ -90,6 +90,11 @@ pre {
     (Corrected in the second printing.)
   </p>
 
+  <p>
+    <b>p.75, ¶4</b>: for "<code>%u</code>", read "%<code>o</code>".
+    (Thanks to William Hannish, 2015-12-21.)
+  </p>
+
   <p>
     <b>p.76</b>: the comment <code>// "time.Duration 5ms0s</code> should have
     a closing double-quotation mark.