diff --git a/set.mm b/set.mm
index 1f638c88a6..7568a9e5c6 100644
--- a/set.mm
+++ b/set.mm
@@ -431417,7 +431417,7 @@ orthogonal vectors (i.e. whose inner product is 0) is the sum of the
 /* Optional link(s) to other versions of the theorem page.  A "*" is replaced
    with the label of the current theorem.  If you need a literal "*" as part
    of the URL, use the alternate URL encoding "%2A". */
-htmlexturl '<A HREF="http://metamath.tirix.org/*.html">'
+htmlexturl '<A HREF="http://metamath.tirix.org/mpests/*.html">'
     + 'Structured version</A>&nbsp;&nbsp; '
     + '<A HREF="https://expln.github.io/metamath/asrt/*.html">'
     + 'Visualization version</A>&nbsp;&nbsp; ';