1 files changed, 7 insertions, 3 deletions
diff --git a/apps/dav/lib/CalDAV/Schedule/IMipService.php b/apps/dav/lib/CalDAV/Schedule/IMipService.php
index 3e8e72bd2e4..50e770e6b40 100644
--- a/apps/dav/lib/CalDAV/Schedule/IMipService.php
+++ b/apps/dav/lib/CalDAV/Schedule/IMipService.php
@@ -70,11 +70,15 @@ class IMipService {
 	}
 
 	/**
-	 * @param string $senderName
-	 * @param $default
+	 * @param string|null $senderName
+	 * @param string $default
 	 * @return string
 	 */
-	public function getFrom(string $senderName, $default): string {
+	public function getFrom(?string $senderName, string $default): string {
+		if ($senderName === null) {
+			return $default;
+		}
+
 		return $this->l10n->t('%1$s via %2$s', [$senderName, $default]);
 	}