diff --git a/3ed-2018/Shapes/Subdivision_Surfaces.html b/3ed-2018/Shapes/Subdivision_Surfaces.html
index b66a38b..2fe5484 100644
--- a/3ed-2018/Shapes/Subdivision_Surfaces.html
+++ b/3ed-2018/Shapes/Subdivision_Surfaces.html
@@ -2684,7 +2684,7 @@
 of other parents.  Only the first three children need to be addressed here; the
 interior child’s neighbor pointers have already been fully initialized.
 Inspection of Figure&nbsp;<a href="#fig:tri-face-split">3.36</a> reveals that the <tt>k</tt>th and
-<tt>PREV(k)</tt>th edges of the <tt>i</tt>th child need to be set.  To set the <tt>k</tt>th
+<tt>PREV(k)</tt>th edges of the <tt>k</tt>th child need to be set.  To set the <tt>k</tt>th
 edge of the <tt>k</tt>th child, we first find the <tt>k</tt>th edge of the parent face, then
 the neighbor parent <tt>f2</tt> across that edge.  If <tt>f2</tt> exists (meaning
 we aren&rsquo;t on a boundary), the neighbor parent index for the vertex