diff --git a/lib/Service/ConfigService.php b/lib/Service/ConfigService.php
index 160b8cdeb..60b1163fb 100644
--- a/lib/Service/ConfigService.php
+++ b/lib/Service/ConfigService.php
@@ -694,7 +694,7 @@ public function linkToRoute(string $route, array $args): string {
 			$knownPath = OC::$WEBROOT;
 		}
 
-		$knownPath = rtrim($knownPath, '/');
+		$knownPath = $knownPath ? rtrim($knownPath, '/') : '';
 		if ($knownPath === '') {
 			return $path;
 		}