diff --git a/doc/lxc-execute.sgml.in b/doc/lxc-execute.sgml.in
index bf9e16eb8..d701b89fe 100644
--- a/doc/lxc-execute.sgml.in
+++ b/doc/lxc-execute.sgml.in
@@ -124,7 +124,7 @@
 	</term>
 	<listitem>
 	  <para>
-	    Executes the <replaceable>command</replaceable> with user ID
+	    Executes the <replaceable>command</replaceable> with user ID (use numerical value)
 	    <replaceable>uid</replaceable> inside the container.
 	  </para>
 	</listitem>
@@ -136,7 +136,7 @@
 	</term>
 	<listitem>
 	  <para>
-	    Executes the <replaceable>command</replaceable> with group ID
+	    Executes the <replaceable>command</replaceable> with group ID (use numerical value)
 	    <replaceable>gid</replaceable> inside the container.
 	  </para>
 	</listitem>