diff --git a/server/migrations.js b/server/migrations.js
index d2d1f4fef..cfbe43c83 100644
--- a/server/migrations.js
+++ b/server/migrations.js
@@ -122,7 +122,7 @@ Migrations.add('use-css-class-for-boards-colors', () => {
     '#499BEA': 'clearblue',
     '#596557': 'natural',
     '#2A80B8': 'modern',
-    '#2a2a2a': moderndark,
+    '#2a2a2a': 'moderndark',
   };
   Boards.find().forEach(board => {
     const oldBoardColor = board.background.color;