diff --git a/reference.html b/reference.html
index 4b09a11..2f5d023 100644
--- a/reference.html
+++ b/reference.html
@@ -310,7 +310,7 @@ can be literals (unquoted strings), strings, or numbers
         <li><code>PEEK(49180)</code> &mdash; See if page2 (&gt; 127) or page1 (&lt; 128)
         <li><code>PEEK(49181)</code> &mdash; See if hires mode (&gt; 127) or lores mode (&lt; 128)
         <li><code>PEEK(49182)</code> &mdash; See if mousetext mode (&gt; 127)
-        <li><code>PEEK(49188)</code> &mdash; See if 80-column mode (&gt; 127)
+        <li><code>PEEK(49183)</code> &mdash; See if 80-column mode (&gt; 127)
 
         <li><code>PEEK(49200)</code> &mdash; Click Speaker (no-op)
         <li><code>PEEK(49248)</code> &mdash; Read Paddle Button #3 &mdash; <em>Use the PageDown key</em>