diff --git a/docs/reference.xml b/docs/reference.xml
index dd908151..4a5ba722 100644
--- a/docs/reference.xml
+++ b/docs/reference.xml
@@ -1640,7 +1640,7 @@
           <arguments>
             <argument token="N" description="path to the sound file"></argument>
             <argument token="V" description="volume adjustment" optional="true" valueNotes="1..255, default is 0"/>
-            <argument token="M" description="maximum simultaneous sounds" optional="true" valueNotes="default 0 (unlimited)"/>
+            <argument token="M" description="maximum simultaneous sounds" optional="true" valueNotes="default -1 (unlimited)"/>
           </arguments>
         </command>
         <command name="mapmodelreset">