diff --git a/doc/src/sgml/release-10.sgml b/doc/src/sgml/release-10.sgml
index aacdd360e0..c72b4c931e 100644
--- a/doc/src/sgml/release-10.sgml
+++ b/doc/src/sgml/release-10.sgml
@@ -8990,7 +8990,7 @@ This was disabled in the PG 9.6 branch so there is no commit here.
 
   </sect2>
 
-  <sect2>
+  <sect2 id="release-10-acknowledgements">
    <title>Acknowledgments</title>
 
    <para>
diff --git a/doc/src/sgml/release-11.sgml b/doc/src/sgml/release-11.sgml
index b129d32264..09b80b8af5 100644
--- a/doc/src/sgml/release-11.sgml
+++ b/doc/src/sgml/release-11.sgml
@@ -3633,7 +3633,7 @@ same commits as above
 
   </sect2>
 
-  <sect2>
+  <sect2 id="release-11-acknowledgements">
    <title>Acknowledgments</title>
 
    <para>