diff --git a/doc/flatpak-config.xml b/doc/flatpak-config.xml
index 366300a50..e23bcc007 100644
--- a/doc/flatpak-config.xml
+++ b/doc/flatpak-config.xml
@@ -52,15 +52,24 @@
         <title>Description</title>
 
         <para>
-            Show and modify the configuration of a flatpak installation.
+            The flatpak config command shows or modifies the configuration of a flatpak installation.
+            The following keys are supported:
         </para>
+        <variablelist>
+            <varlistentry>
+                <term><varname>languages</varname></term>
+                <listitem><para>
+                   The languages that are included when installing Locale extensions.
+                   The value is a semicolon-separated list of two-letter language codes,
+                   or one of the special values * or all. If this key is unset, flatpak
+                   defaults to including just the current locale.
+                </para></listitem>
+            </varlistentry>
+        </variablelist>
 
         <para>
             For configuration of individual remotes, see
             <citerefentry><refentrytitle>flatpak-remote-modify</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
-        </para>
-
-        <para>
             For configuration of individual applications, see
             <citerefentry><refentrytitle>flatpak-override</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
         </para>