diff --git a/manifest.yaml b/manifest.yaml
index 12371e4..1c5cf2a 100644
--- a/manifest.yaml
+++ b/manifest.yaml
@@ -43,7 +43,7 @@ dublin_core:
         - 
             identifier: tw
             language: en
-            version: ?
+            version: '?'
     subject: Translation Words
     title: Translation Words
     type: dict