diff --git a/src/web/bookform.ts b/src/web/bookform.ts
index fb1c0c1..bce6355 100644
--- a/src/web/bookform.ts
+++ b/src/web/bookform.ts
@@ -23,15 +23,18 @@ const BookForm = () => {
         <input placeholder="author name" ...=${spread(authorProps)}>
         <button @click=${async () => {
             try {
-                const data = await schema.validate({
+                const newBook = await schema.validate({
                     author: authorProps[".value"],
                     title: titleProps[".value"]
                 });
 
-                await addBook({ variables: data, update: (cache, result) => {
-                    const list: any = cache.readQuery({ query: GetBooks });
-                    cache.writeQuery({ query: GetBooks, data: { books: [...list.books, result.data.addBook] }});
-                }});
+                await addBook({
+                    variables: newBook,
+                    update: (cache, { data }) => {
+                        const { books }: any = cache.readQuery({ query: GetBooks });
+                        cache.writeQuery({ query: GetBooks, data: { books: [...books, data.addBook] }});
+                    }
+                });
 
                 setTitle("");
                 setAuthor("");