diff --git a/html/upgrade.iredapd.html b/html/upgrade.iredapd.html
index c0fb56dc..277d6666 100644
--- a/html/upgrade.iredapd.html
+++ b/html/upgrade.iredapd.html
@@ -30,9 +30,13 @@ supported by iRedMail.</p>
 </code></pre>
 
 <p>That's all.</p>
-<p>Notes:</p>
+<p>Important notes:</p>
 <ul>
 <li>
+<p>Plugin <code>amavisd_wblist</code> is required if you manage white/blacklists with
+  iRedAdmin-Pro.</p>
+</li>
+<li>
 <p>It's recommended to enable plugin <code>reject_null_sender</code> in iRedAPD-1.4.4 or
   newer releases to prevent authenticated user sending spam as null sender.</p>
 </li>
diff --git a/html/upgrade.iredmail.0.8.7-0.9.0.html b/html/upgrade.iredmail.0.8.7-0.9.0.html
index f8b772c7..d06cc617 100644
--- a/html/upgrade.iredmail.0.8.7-0.9.0.html
+++ b/html/upgrade.iredmail.0.8.7-0.9.0.html
@@ -83,6 +83,8 @@ latest stable release immediately: <a href="http://trac.roundcube.net/wiki/Howto
 <h3 id="upgrade-iredapd-postfix-policy-server-to-the-latest-144">Upgrade iRedAPD (Postfix policy server) to the latest 1.4.4</h3>
 <p>iRedAPD-1.4.4 brings several new plugins, and works with Postfix parameter
 <code>smtpd_end_of_data_restrictions</code> (protocol state <code>END-OF-MESSAGE</code>).</p>
+<p>Important note: If you want to manage white/blacklists with iRedAdmin-Pro,
+you have to enable plugin <code>amavisd_wblist</code>.</p>
 <p>Please follow below tutorial to upgrade iRedAPD to the latest stable release:
 <a href="./upgrade.iredapd.html">How to upgrade iRedAPD-1.4.0 or later versions to the latest stable release</a></p>
 <h3 id="upgrade-iredadmin-open-source-edition-to-the-latest-stable-release">Upgrade iRedAdmin (open source edition) to the latest stable release</h3>
diff --git a/upgrade/0-upgrade.iredmail.0.8.7-0.9.0.md b/upgrade/0-upgrade.iredmail.0.8.7-0.9.0.md
index f2255580..e0283831 100644
--- a/upgrade/0-upgrade.iredmail.0.8.7-0.9.0.md
+++ b/upgrade/0-upgrade.iredmail.0.8.7-0.9.0.md
@@ -43,6 +43,9 @@ latest stable release immediately: [How to upgrade Roundcube](http://trac.roundc
 iRedAPD-1.4.4 brings several new plugins, and works with Postfix parameter
 `smtpd_end_of_data_restrictions` (protocol state `END-OF-MESSAGE`).
 
+Important note: If you want to manage white/blacklists with iRedAdmin-Pro,
+you have to enable plugin `amavisd_wblist`.
+
 Please follow below tutorial to upgrade iRedAPD to the latest stable release:
 [How to upgrade iRedAPD-1.4.0 or later versions to the latest stable release](./upgrade.iredapd.html)
 
diff --git a/upgrade/upgrade.iredapd.md b/upgrade/upgrade.iredapd.md
index 47a6ac26..1d0d2353 100644
--- a/upgrade/upgrade.iredapd.md
+++ b/upgrade/upgrade.iredapd.md
@@ -20,7 +20,10 @@ supported by iRedMail.
 
 That's all.
 
-Notes:
+Important notes:
+
+* Plugin `amavisd_wblist` is required if you manage white/blacklists with
+  iRedAdmin-Pro.
 
 * It's recommended to enable plugin `reject_null_sender` in iRedAPD-1.4.4 or
   newer releases to prevent authenticated user sending spam as null sender.