diff --git a/man/systemd-firstboot.xml b/man/systemd-firstboot.xml
index 8cdc297a0e..539422ab98 100644
--- a/man/systemd-firstboot.xml
+++ b/man/systemd-firstboot.xml
@@ -63,8 +63,14 @@
 
     <para><command>systemd-firstboot</command> initializes the most
     basic system settings interactively on the first boot, or
-    optionally non-interactively when a system image is created. The
-    following settings may be set up:</para>
+    optionally non-interactively when a system image is created.
+    The service is started if <varname>ConditionFirstBoot=yes</varname>
+    is satisfied. This essentially means that <filename>/etc</filename>
+    is empty, see
+    <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+    for details.</para>
+
+    <para>The following settings may be set up:</para>
 
     <itemizedlist>
       <listitem><para>The system locale, more specifically the two