diff --git a/apps/dav/lib/Connector/LegacyPublicAuth.php b/apps/dav/lib/Connector/LegacyPublicAuth.php
index c2cc81103bd4f..82a474d4bed22 100644
--- a/apps/dav/lib/Connector/LegacyPublicAuth.php
+++ b/apps/dav/lib/Connector/LegacyPublicAuth.php
@@ -63,7 +63,7 @@ public function __construct(IRequest $request,
 
 		// setup realm
 		$defaults = new \OCP\Defaults();
-		$this->realm = $defaults->getName();
+		$this->realm = $defaults->getName() ?: 'Nextcloud';
 	}
 
 	/**
diff --git a/apps/dav/lib/Connector/Sabre/Auth.php b/apps/dav/lib/Connector/Sabre/Auth.php
index 243b92e63f744..c2e343d8656f1 100644
--- a/apps/dav/lib/Connector/Sabre/Auth.php
+++ b/apps/dav/lib/Connector/Sabre/Auth.php
@@ -75,7 +75,7 @@ public function __construct(ISession $session,
 
 		// setup realm
 		$defaults = new \OCP\Defaults();
-		$this->realm = $defaults->getName();
+		$this->realm = $defaults->getName() ?: 'Nextcloud';
 	}
 
 	/**
diff --git a/apps/dav/lib/Connector/Sabre/BearerAuth.php b/apps/dav/lib/Connector/Sabre/BearerAuth.php
index 4d9599b97a3da..6fd61c44b3452 100644
--- a/apps/dav/lib/Connector/Sabre/BearerAuth.php
+++ b/apps/dav/lib/Connector/Sabre/BearerAuth.php
@@ -47,7 +47,7 @@ public function __construct(IUserSession $userSession,
 
 		// setup realm
 		$defaults = new \OCP\Defaults();
-		$this->realm = $defaults->getName();
+		$this->realm = $defaults->getName() ?: 'Nextcloud';
 	}
 
 	private function setupUserFs($userId) {