diff --git a/ChangeLog b/ChangeLog
index 17e66d70..ff5421fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-11-17  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* man/usermod.8.xml: Document the differences between locking an
+	account and locking a password.
+
 2007-11-17  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* NEWS, src/usermod.c: Refuse to unlock an account when it would
diff --git a/man/usermod.8.xml b/man/usermod.8.xml
index 3d6cc6a3..c86dd4bd 100644
--- a/man/usermod.8.xml
+++ b/man/usermod.8.xml
@@ -158,6 +158,12 @@
 	    can't use this option with <option>-p</option> or
 	    <option>-U</option>.
 	  </para>
+	  <para>
+	    Note: if you wish to lock the account (not only access with a
+	    password), you should also set the
+	    <replaceable>EXPIRE_DATE</replaceable> to
+	    <replaceable>1</replaceable>.
+	  </para>
 	</listitem>
       </varlistentry>
       <varlistentry>
@@ -224,6 +230,14 @@
 	    encrypted password. You can't use this option with
 	    <option>-p</option> or <option>-L</option>.
 	  </para>
+	  <para>
+	    Note: if you wish to unlock the account (not only access with a
+	    password), you should also set the
+	    <replaceable>EXPIRE_DATE</replaceable> (for example to
+	    <replaceable>99999</replaceable>, or to the
+	    <replaceable>EXPIRE</replaceable> value from
+	    <filename>/etc/default/useradd</filename>).
+	  </para>
 	</listitem>
       </varlistentry>
     </variablelist>