diff --git a/doc/protocol.xml b/doc/protocol.xml
index 792227a1a..5418ea8f8 100644
--- a/doc/protocol.xml
+++ b/doc/protocol.xml
@@ -270,6 +270,24 @@
                   </returnvalue>
                 </para>
               </listitem>
+              <listitem>
+                <para>
+                  <varname>nextsong</varname>:
+                  <footnoteref linkend="since_0_15"/>
+                  <returnvalue> playlist song number of the next
+                  song to be played
+                  </returnvalue>
+                </para>
+              </listitem>
+              <listitem>
+                <para>
+                  <varname>nextsongid</varname>:
+                  <footnoteref linkend="since_0_15"/>
+                  <returnvalue>playlist songid of the next song
+                  to be played
+                  </returnvalue>
+                </para>
+              </listitem>
               <listitem>
                 <para>
                   <varname>time</varname>: