diff --git a/configure.php b/configure.php
index 1a07591639..1f52de3608 100755
--- a/configure.php
+++ b/configure.php
@@ -839,6 +839,9 @@ function xinclude_residual_fixup( DOMDocument $dom )
case "variablelist":
$fixup = "$alert";
break;
+ case "classsynopsis":
+ $fixup = "$alert";
+ break;
default:
echo " (Unknown parent of failed XInclude: $parent)\n";
$hardfail = true;