diff --git a/doc/src/sgml/spgist.sgml b/doc/src/sgml/spgist.sgml
index 56827e520dd..0cd58169aa4 100644
--- a/doc/src/sgml/spgist.sgml
+++ b/doc/src/sgml/spgist.sgml
@@ -134,7 +134,7 @@
  <para>
   Of the two operator classes for type <type>point</>,
   <literal>quad_point_ops</> is the default.  <literal>kd_point_ops</>
-  supports the same operators but uses a different index data structure which
+  supports the same operators but uses a different index data structure that
   may offer better performance in some applications.
  </para>