diff --git a/errata.html b/errata.html
index 7e19ac9..dc1a70d 100644
--- a/errata.html
+++ b/errata.html
@@ -41,6 +41,15 @@ pre {
     (Thanks to Victor Farazdagi, 2015-11-30.)
   </p>
 
+  <p>
+    <b>p.38, ¶4</b>: For "value of the underlying type", read
+    "value of an unnamed type with the same underlying type".
+    <!-- The "unnamed" restriction is there for basic types, which
+         are named, so it forbids Celsius(0)==float64(0), for instance.
+     -->
+    (Thanks to Carlos Romero Brox, 2015-12-19.)
+  </p>
+
   <p>
     <b>p.40, ¶1</b>: The paragraph should end with a period, not a comma.
     (Thanks to Victor Farazdagi, 2015-11-30.)