diff --git a/doc/src/sgml/xfunc.sgml b/doc/src/sgml/xfunc.sgml
index a7c170476a..1d0b65193e 100644
--- a/doc/src/sgml/xfunc.sgml
+++ b/doc/src/sgml/xfunc.sgml
@@ -3668,6 +3668,12 @@ extern bool InjectionPointDetach(const char *name);
      using <literal>InjectionPointDetach</literal>.
     </para>
 
+    <para>
+     An example can be found in
+     <filename>src/test/modules/injection_points</filename> in the PostgreSQL
+     source tree.
+    </para>
+
     <para>
      Enabling injections points requires
      <option>--enable-injection-points</option> with