diff --git a/errata.html b/errata.html
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@@ -197,8 +197,8 @@ pre {
   </p>
 
   <p>
-    <b>p.235, ¶3</b>: <code>makeThumnails</code> refers to the second draft
-    of the function, <code>makeThumnails2</code>.
+    <b>p.235, ¶3</b>: <code>makeThumbnails</code> refers to the second draft
+    of the function, <code>makeThumbnails2</code>.
     (Thanks to 有賀功 Isao Aruga, 2016-07-13.)
   </p>