diff --git a/doc/manual/conf-file.xml b/doc/manual/conf-file.xml
index fa9149834..754c4d029 100644
--- a/doc/manual/conf-file.xml
+++ b/doc/manual/conf-file.xml
@@ -425,12 +425,13 @@ flag, e.g. <literal>--option gc-keep-outputs false</literal>.</para>
 
   <varlistentry><term><literal>auto-optimise-store</literal></term>
 
-    <listitem><para>If set to <literal>true</literal> (the default),
-    Nix automatically detects files in the store that have identical
+    <listitem><para>If set to <literal>true</literal>, Nix
+    automatically detects files in the store that have identical
     contents, and replaces them with hard links to a single copy.
-    This saves disk space.  If set to <literal>false</literal>, you
-    can still run <command>nix-store --optimise</command> to get rid
-    of duplicate files.</para></listitem>
+    This saves disk space.  If set to <literal>false</literal> (the
+    default), you can still run <command>nix-store
+    --optimise</command> to get rid of duplicate
+    files.</para></listitem>
 
   </varlistentry>