diff --git a/doc/manual/advanced-topics/diff-hook.xml b/doc/manual/advanced-topics/diff-hook.xml
index f01ab71b3..85cfdfc02 100644
--- a/doc/manual/advanced-topics/diff-hook.xml
+++ b/doc/manual/advanced-topics/diff-hook.xml
@@ -5,10 +5,7 @@
       version="5.0"
       >
 
-<title>Verifying Build Reproducibility with <option linkend="conf-diff-hook">diff-hook</option></title>
-
-<subtitle>Check build reproducibility by running builds multiple times
-and comparing their results.</subtitle>
+<title>Verifying Build Reproducibility</title>
 
 <para>Specify a program with Nix's <xref linkend="conf-diff-hook" /> to
 compare build results when two builds produce different results. Note:
diff --git a/doc/manual/advanced-topics/post-build-hook.xml b/doc/manual/advanced-topics/post-build-hook.xml
index 6cc286ee1..1480ab86a 100644
--- a/doc/manual/advanced-topics/post-build-hook.xml
+++ b/doc/manual/advanced-topics/post-build-hook.xml
@@ -6,8 +6,6 @@
       >
 
 <title>Using the <option linkend="conf-post-build-hook">post-build-hook</option></title>
-<subtitle>Uploading to an S3-compatible binary cache after each build</subtitle>
-
 
 <section xml:id="chap-post-build-hook-caveats">
   <title>Implementation Caveats</title>