diff --git a/.github/workflows/phpunit.yml b/.github/workflows/phpunit.yml
index 67fe092..3e4e60a 100644
--- a/.github/workflows/phpunit.yml
+++ b/.github/workflows/phpunit.yml
@@ -3,6 +3,11 @@ name: PHPUnit Plugin Tests
 on: [push, pull_request]
 
 jobs:
-  lint:
-    name: Run PHPUnit test suites
+  phpunit5:
+    name: Run PHPUnit test suites - Elgg 5
     uses: ColdTrick/.github/.github/workflows/phpunit.yml@master
+  phpunit6:
+    name: Run PHPUnit test suites - Elgg 6
+    uses: ColdTrick/.github/.github/workflows/phpunit.yml@master
+    with:
+      elgg_major_version: 6
diff --git a/README.md b/README.md
index b487cde..1814778 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 Test Panel
 ==========
 
-![Elgg 5.0](https://img.shields.io/badge/Elgg-5.0-green.svg)
+![Elgg 6.0](https://img.shields.io/badge/Elgg-6.0-green.svg)
 ![Lint Checks](https://github.com/ColdTrick/test_panel/actions/workflows/lint.yml/badge.svg?event=push)
 [![Latest Stable Version](https://poser.pugx.org/coldtrick/test_panel/v/stable.svg)](https://packagist.org/packages/coldtrick/test_panel)
 [![License](https://poser.pugx.org/coldtrick/test_panel/license.svg)](https://packagist.org/packages/coldtrick/test_panel)
diff --git a/classes/ColdTrick/TestPanel/EmailHandler.php b/classes/ColdTrick/TestPanel/EmailHandler.php
index e65dcd5..e5942fb 100644
--- a/classes/ColdTrick/TestPanel/EmailHandler.php
+++ b/classes/ColdTrick/TestPanel/EmailHandler.php
@@ -40,7 +40,7 @@ public static function validate(\Elgg\Event $event): ?bool {
 		}
 		
 		$allowed_emails = test_panel_get_panel_members_email_addresses();
-		if (empty($allowed_emails) || !is_array($allowed_emails)) {
+		if (empty($allowed_emails)) {
 			// nobody is allowed (shouldn't happen)
 			return false;
 		}
diff --git a/composer.json b/composer.json
index a892923..e1645aa 100644
--- a/composer.json
+++ b/composer.json
@@ -10,6 +10,6 @@
 		"issues": "https://github.com/ColdTrick/test_panel/issues"
 	},
 	"conflict": {
-		"elgg/elgg": "<5.0"
+		"elgg/elgg": "<6.0"
 	}
 }
diff --git a/composer.lock b/composer.lock
index 458f070..89969d7 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "fadb48929e2775b231ac24af524a4696",
+    "content-hash": "9c1d00dbe6f2cb1caf8b5ba4375dd948",
     "packages": [],
     "packages-dev": [],
     "aliases": [],
diff --git a/lib/functions.php b/lib/functions.php
index ab49747..c8ca445 100644
--- a/lib/functions.php
+++ b/lib/functions.php
@@ -3,6 +3,8 @@
  * All helper functions are bundled here
  */
 
+use Elgg\Database\MetadataTable;
+use Elgg\Database\RelationshipsTable;
 use Elgg\Database\Select;
 
 /**
@@ -41,12 +43,12 @@ function test_panel_get_panel_members_email_addresses(): array {
 	
 	$result = [];
 	
-	$select = Select::fromTable('metadata', 'md');
-	$select->select('md.value');
-	$select->joinEntitiesTable('md', 'entity_guid', 'inner', 'e');
+	$select = Select::fromTable(MetadataTable::TABLE_NAME, 'md');
+	$select->select("{$select->getTableAlias()}.value");
+	$select->joinEntitiesTable($select->getTableAlias(), 'entity_guid', 'inner', 'e');
 	$select->joinMetadataTable('e', 'guid', null, 'inner', 'mda');
 	$select->andWhere($select->compare('e.type', '=', 'user', ELGG_VALUE_STRING));
-	$select->andWhere($select->compare('md.name', '=', 'email', ELGG_VALUE_STRING));
+	$select->andWhere($select->compare("{$select->getTableAlias()}.name", '=', 'email', ELGG_VALUE_STRING));
 	
 	// admins
 	$ands = $select->merge([
@@ -57,12 +59,12 @@ function test_panel_get_panel_members_email_addresses(): array {
 	// or group member
 	$group_guids = test_panel_get_group_guids();
 	if (!empty($group_guids)) {
-		$group_members = $select->subquery('entity_relationships');
+		$group_members = $select->subquery(RelationshipsTable::TABLE_NAME);
 		$group_members->select('guid_one')
 			->where($select->compare('relationship', '=', 'member', ELGG_VALUE_STRING))
 			->andWhere($select->compare('guid_two', 'in', $group_guids, ELGG_VALUE_GUID));
 		
-		$or = $select->compare('md.entity_guid', 'in', $group_members->getSQL());
+		$or = $select->compare("{$select->getTableAlias()}.entity_guid", 'in', $group_members->getSQL());
 		
 		$ands = $select->merge([$ands, $or], 'OR');
 	}
diff --git a/views/default/plugins/test_panel/settings.php b/views/default/plugins/test_panel/settings.php
index 9245b66..5404a8f 100644
--- a/views/default/plugins/test_panel/settings.php
+++ b/views/default/plugins/test_panel/settings.php
@@ -26,8 +26,7 @@
 	'switch' => true,
 ]);
 
-$title = elgg_echo('test_panel:settings:message');
-
+// message to non-test members
 $content = elgg_view_field([
 	'#type' => 'text',
 	'#label' => elgg_echo('test_panel:settings:message_title'),
@@ -42,4 +41,4 @@
 	'value' => $plugin->message_content ?? elgg_echo('limited_access'),
 ]);
 
-echo elgg_view_module('info', $title, $content);
+echo elgg_view_module('info', elgg_echo('test_panel:settings:message'), $content);