diff --git a/src/user-profile/shelf-routes.ts b/src/user-profile/shelf-routes.ts
index fe7a448..856dbd2 100644
--- a/src/user-profile/shelf-routes.ts
+++ b/src/user-profile/shelf-routes.ts
@@ -120,23 +120,23 @@ shelfRoutes.put('/update/', jwtAuthentication, async (request, response) => {
 
     
     for (let i = 0; i < updatedAddedWords.length; i += 1) {
-        if (!updatedAddedWords[i].word || !updatedAddedWords[i].isArchived || 
-            !updatedAddedWords[i].isFavourite || !updatedAddedWords[i].nextRevisionDateTime || 
-            !updatedAddedWords[i].notes || !updatedAddedWords[i].revisionHistory || !updatedAddedWords[i].spaceBetweenRecall) {
+        if (!updatedAddedWords[i].word || updatedAddedWords[i].isArchived === undefined || 
+            updatedAddedWords[i].isFavourite === undefined || !updatedAddedWords[i].nextRevisionDateTime || 
+            updatedAddedWords[i].notes === undefined || updatedAddedWords[i].revisionHistory === undefined || 
+            !updatedAddedWords[i].spaceBetweenRecall) {
                 response.status(400);
                 response.send("Missing key in " + JSON.stringify(updatedAddedWords[i]));
                 return;
         }
 
         const wordId = updatedAddedWords[i].word;
-        
         const matchedWord = await wordCollection.findOne({
             _id: new ObjectId(wordId)
         });
 
         if (!matchedWord) {
             response.status(400);
-            response.send("Word with ID " + updatedAddedWords[i] + " is not present in the library" );
+            response.send("Word with ID " + updatedAddedWords[i].word + " is not present in the library" );
             return;
         }
     }