diff --git a/prologue/why.xml b/prologue/why.xml
index f2b4a5d18..fac1e1559 100644
--- a/prologue/why.xml
+++ b/prologue/why.xml
@@ -232,7 +232,9 @@
         <para>Gperf</para>
 
         <para>This package produces a program that generates a perfect hash
-        function from a set of keys. It is required by Eudev.</para>
+        function from a set of keys. It is required by
+        <phrase revision='sysv'>Eudev</phrase>
+        <phrase revision='systemd'>Systemd</phrase>.</para>
       </listitem>
 
       <listitem>