diff --git a/tutorials/online/sidenote-format-fact.html b/tutorials/online/sidenote-format-fact.html
index 219243f..62ed961 100644
--- a/tutorials/online/sidenote-format-fact.html
+++ b/tutorials/online/sidenote-format-fact.html
@@ -15,7 +15,7 @@ <h2>Syntax for <i>fact</i> statements</h2>
   }
 </pre></b>
 
-<p> Facts do not need to have names, and are never refered to by name.
+<p> Facts do not need to have names, and are never referred to by name.
     However, good names improve clarity tremendously. </p>
 
 <p> <i>A warning</i><b>:</b> When Alloy searches for examples, it