diff --git a/client/lib/dialogWithBoardSwimlaneListCard.js b/client/lib/dialogWithBoardSwimlaneListCard.js
index 8d07a3a3d..1c0bbaeec 100644
--- a/client/lib/dialogWithBoardSwimlaneListCard.js
+++ b/client/lib/dialogWithBoardSwimlaneListCard.js
@@ -23,7 +23,7 @@ export class DialogWithBoardSwimlaneListCard extends DialogWithBoardSwimlaneList
   /** returns all available cards of the current list */
   cards() {
     const list = Lists.findOne(this.selectedListId.get());
-    let ret = {}
+    let ret = [];
     if (list) {
       ret = list.cards(this.selectedSwimlaneId.get());
     }