diff --git a/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php b/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php
index eda2399a780f9..5d9431e108ffd 100644
--- a/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php
+++ b/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php
@@ -69,7 +69,7 @@ public function beforeHandler(RequestInterface $request) {
 		preg_match(IRequest::USER_AGENT_CLIENT_DESKTOP, $userAgent, $versionMatches);
 		if (isset($versionMatches[1]) &&
 			version_compare($versionMatches[1], $minimumSupportedDesktopVersion) === -1) {
-			throw new \Sabre\DAV\Exception\Forbidden('Unsupported client version.');
+			throw new \Sabre\DAV\Exception\Forbidden('This client is unsupported by the server: upgrade to the minimum required version '.$minimumSupportedDesktopVersion);
 		}
 	}
 }