diff --git a/general/genlib/boost.xml b/general/genlib/boost.xml
index 6eaa9fdbd7..a2d3dc35c5 100644
--- a/general/genlib/boost.xml
+++ b/general/genlib/boost.xml
@@ -23,7 +23,7 @@
   <title>Boost-&boost-version;</title>
 
   <indexterm zone="boost">
-    <primary sortas="l-boost">boost</primary>
+    <primary sortas="a-boost">boost</primary>
   </indexterm>
 
   <sect2 role="package">