diff --git a/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php b/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php
index d0847a07f1c74..32f0ee8bdb167 100644
--- a/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php
+++ b/apps/dav/lib/Connector/Sabre/BlockLegacyClientPlugin.php
@@ -66,7 +66,7 @@ public function beforeHandler(RequestInterface $request) {
 		}
 
 		$minimumSupportedDesktopVersion = $this->config->getSystemValue('minimum.supported.desktop.version', '2.3.0');
-		$maximumSupportedDesktopVersion = $this->config->getSystemValue('maximum.supported.desktop.version', '');
+		$maximumSupportedDesktopVersion = $this->config->getSystemValueString('maximum.supported.desktop.version', '');
 		preg_match(IRequest::USER_AGENT_CLIENT_DESKTOP, $userAgent, $versionMatches);
 		if (isset($versionMatches[1]) &&
 			version_compare($versionMatches[1], $minimumSupportedDesktopVersion) === -1 ||