diff --git a/lib/Service/CardService.php b/lib/Service/CardService.php
index d77cb0cea..ba644bd1a 100644
--- a/lib/Service/CardService.php
+++ b/lib/Service/CardService.php
@@ -355,6 +355,8 @@ public function update($id, $title, $stackId, $type, $owner, $description = '',
 		}
 		if ($done !== null) {
 			$card->setDone($done->getValue());
+		} else {
+			$card->setDone(null);
 		}