diff --git a/administrator/components/com_jedchecker/language/en-GB/en-GB.com_jedchecker.ini b/administrator/components/com_jedchecker/language/en-GB/en-GB.com_jedchecker.ini
index 655f058..a8717ec 100644
--- a/administrator/components/com_jedchecker/language/en-GB/en-GB.com_jedchecker.ini
+++ b/administrator/components/com_jedchecker/language/en-GB/en-GB.com_jedchecker.ini
@@ -49,7 +49,7 @@ COM_JEDCHECKER_INFO_XML_NAME_RESERVED_KEYWORDS="Keywords such as module, plugin
 COM_JEDCHECKER_INFO_XML_NAME_VERSION="Version in name/title"
 COM_JEDCHECKER_INFO_XML_NAME_JOOMLA="An extension name can't start with the word 'Joomla'"
 COM_JEDCHECKER_INFO_XML_NAME_JOOMLA_DERIVATIVE="Extensions that use 'Joomla' or a derivative of Joomla in the extension name need to be licensed by OSM"
-COM_JEDCHECKER_INFO_XML_URL_JOOMLA_DERIVATIVE="Extensions that use 'Joomla' or a derivative of Joomla in the domain name need to be licensed by OSM"
+COM_JEDCHECKER_INFO_XML_URL_JOOMLA_DERIVATIVE="Extensions that use 'Joomla' or a derivative of Joomla in the domain name ('%s') need to be licensed by OSM"
 COM_JEDCHECKER_INFO_XML_NAME_ADMIN_MENU="The admin menu name '%1$s' isn't the same as the extension name '%2$s'"
 COM_JEDCHECKER_INFO_XML_NAME_PLUGIN_FORMAT="The name of the plugin ('%s') must comply with the JED naming conventions in the form '{Type} - {Extension Name}'"
 COM_JEDCHECKER_RULE_PH1="PHP Headers missing GPL License Notice"
diff --git a/administrator/components/com_jedchecker/libraries/rules/xmlinfo.php b/administrator/components/com_jedchecker/libraries/rules/xmlinfo.php
index c3e3921..b010207 100644
--- a/administrator/components/com_jedchecker/libraries/rules/xmlinfo.php
+++ b/administrator/components/com_jedchecker/libraries/rules/xmlinfo.php
@@ -247,8 +247,19 @@ class JedcheckerRulesXMLinfo extends JEDcheckerRule
 		if (stripos($url, 'joom') !== false)
 		{
 			$domain = (strpos($url, '//') === false) ? $url : parse_url(trim($url), PHP_URL_HOST);
-			if (stripos($domain, 'joom') !== false) {
-				$this->report->addWarning($file, JText::_('COM_JEDCHECKER_INFO_XML_URL_JOOMLA_DERIVATIVE'));
+
+			if (stripos($domain, 'joom') !== false)
+			{
+				// Remove "www." subdomain prefix
+				$domain = preg_replace('/^www\./', '', $domain);
+
+				// Approved domains from https://tm.joomla.org/approved-domains.html
+				$approvedDomains = file(__DIR__ . '/xmlinfo/approved-domains.txt', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+
+				if (!in_array($domain, $approvedDomains, true))
+				{
+					$this->report->addError($file, JText::sprintf('COM_JEDCHECKER_INFO_XML_URL_JOOMLA_DERIVATIVE', $url));
+				}
 			}
 		}
 
diff --git a/administrator/components/com_jedchecker/libraries/rules/xmlinfo/approved-domains.txt b/administrator/components/com_jedchecker/libraries/rules/xmlinfo/approved-domains.txt
new file mode 100644
index 0000000..6e8c234
--- /dev/null
+++ b/administrator/components/com_jedchecker/libraries/rules/xmlinfo/approved-domains.txt
@@ -0,0 +1,46 @@
+joomla.org
+
+hotjoomlatemplates.com
+joomlanl.nl
+joomla-templates.com
+joomla-update.org
+joomlaportal.ru
+joomlavia.com
+joomlatranslate.com
+joomlamarketplace.online
+hotjoomlatemplates.com
+joomlatema.net
+joomla.it
+joomlaalger.org
+joomla.cafe
+joomlatwincities.org
+joomlausersnj.com
+joomlausersnyc.org
+joomlact.org
+joomlachicagonorth.com
+joomlanh.org
+joomlanh.org
+joomlacarioca.com.br
+novajoomla.com
+joomlazur.com
+joomladallas.org
+joomlariodejaneiro.com.br
+joomlatenerife.org
+joomlage.com
+joomlamadrid.org
+joomschool.com
+usingjoomla.com
+joomla.cymru
+joomlavigo.es
+jug-warszawa.joomla.pl
+joomlavalencia.net
+jug-silesia.joomla.pl
+jug-poznan.joomla.pl
+joomla-canberra.org.au
+joomlapay.com
+joomlalondon.co.uk
+mobilejoomla.com/
+myjoomla.com
+joomlacontenteditor.net
+joomlalabs.com
+modernjoomla.com