diff --git a/phpBB/phpbb/notification/method/webpush.php b/phpBB/phpbb/notification/method/webpush.php
index 271e23dffe..a5a3b5e699 100644
--- a/phpBB/phpbb/notification/method/webpush.php
+++ b/phpBB/phpbb/notification/method/webpush.php
@@ -48,6 +48,9 @@ class webpush extends messenger_base implements extended_method_interface
 	/** @var string Notification push subscriptions table */
 	protected $push_subscriptions_table;
 
+	/** @var int Fallback size for padding if endpoint is mozilla, see https://github.com/web-push-libs/web-push-php/issues/108#issuecomment-2133477054 */
+	const MOZILLA_FALLBACK_PADDING = 2820;
+
 	/**
 	 * Notification Method Web Push constructor
 	 *
@@ -218,6 +221,7 @@ class webpush extends messenger_base implements extended_method_interface
 			{
 				try
 				{
+					$this->set_endpoint_padding($web_push, $subscription['endpoint']);
 					$push_subscription = Subscription::create([
 						'endpoint'			=> $subscription['endpoint'],
 						'keys'				=> [
@@ -430,4 +434,27 @@ class webpush extends messenger_base implements extended_method_interface
 
 		$this->remove_subscriptions($remove_subscriptions);
 	}
+
+	/**
+	 * Set web push padding for endpoint
+	 *
+	 * @param \Minishlink\WebPush\WebPush $web_push
+	 * @param string $endpoint
+	 *
+	 * @return void
+	 */
+	protected function set_endpoint_padding(\Minishlink\WebPush\WebPush $web_push, string $endpoint): void
+	{
+		if (str_contains($endpoint, 'mozilla.com') || str_contains($endpoint, 'mozaws.net'))
+		{
+			try
+			{
+				$web_push->setAutomaticPadding(self::MOZILLA_FALLBACK_PADDING);
+			}
+			catch (\Exception)
+			{
+				// This shouldn't happen since we won't pass padding length outside limits
+			}
+		}
+	}
 }
diff --git a/tests/notification/notification_method_webpush_test.php b/tests/notification/notification_method_webpush_test.php
index ff95c74b09..1116a62c6f 100644
--- a/tests/notification/notification_method_webpush_test.php
+++ b/tests/notification/notification_method_webpush_test.php
@@ -653,6 +653,47 @@ class notification_method_webpush_test extends phpbb_tests_notification_base
 		$this->assertCount(0, $cur_notifications, 'Assert that no notifications have been pruned');
 	}
 
+	public function data_set_endpoint_padding(): array
+	{
+		return [
+			[
+				'foo.mozilla.com',
+				webpush::MOZILLA_FALLBACK_PADDING
+			],
+			[
+				'foo.mozaws.net',
+				webpush::MOZILLA_FALLBACK_PADDING
+			],
+			[
+				'foo.android.googleapis.com',
+				\Minishlink\WebPush\Encryption::MAX_COMPATIBILITY_PAYLOAD_LENGTH,
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider data_set_endpoint_padding
+	 */
+	public function test_set_endpoint_padding($endpoint, $expected_padding): void
+	{
+		$web_push_reflection = new \ReflectionMethod($this->notification_method_webpush, 'set_endpoint_padding');
+		$web_push_reflection->setAccessible(true);
+
+		$auth = [
+			'VAPID' => [
+				'subject' => generate_board_url(),
+				'publicKey' => $this->config['webpush_vapid_public'],
+				'privateKey' => $this->config['webpush_vapid_private'],
+			],
+		];
+
+		$web_push = new \Minishlink\WebPush\WebPush($auth);
+
+		$this->assertEquals(\Minishlink\WebPush\Encryption::MAX_COMPATIBILITY_PAYLOAD_LENGTH, $web_push->getAutomaticPadding());
+		$web_push_reflection->invoke($this->notification_method_webpush, $web_push, $endpoint);
+		$this->assertEquals($expected_padding, $web_push->getAutomaticPadding());
+	}
+
 	protected function create_subscription_for_user($user_id, bool $invalidate_endpoint = false): array
 	{
 		$client = new \GuzzleHttp\Client();