diff --git a/src/commands/CreateBookFromClipboardCommand.ts b/src/commands/CreateBookFromClipboardCommand.ts
index 22260b9..b196540 100644
--- a/src/commands/CreateBookFromClipboardCommand.ts
+++ b/src/commands/CreateBookFromClipboardCommand.ts
@@ -1,6 +1,7 @@
 import { Notice } from "obsidian";
 import { Command } from "./Command";
 import { bookSchema, type Book } from "@src/types";
+import z from "zod/v4";
 
 
 export class CreateBookFromClipboardCommand extends Command {
@@ -15,16 +16,16 @@ export class CreateBookFromClipboardCommand extends Command {
 
 	async callback() {
 		const data = await navigator.clipboard.readText();
-		const { data: book, success, error } = await bookSchema.safeParseAsync(JSON.parse(data));
+		const result = await bookSchema.safeParseAsync(JSON.parse(data));
 
-		if (!success) {
-			console.error(error.message);
-			new Notice("There is not a valid book in the clipboard. Check console for details");
+		if (!result.success) {
+			console.log("Invalid book: ", result.error)
+			new Notice("Invalid book\n" + z.prettifyError(result.error));
 			return
 		}
 
 		try {
-			await this.createEntry(book);
+			await this.createEntry(result.data);
 		} catch (error) {
 			console.error("Failed to create book:", error);
 			new Notice("Failed to create book. Check console for details.");
diff --git a/src/types.ts b/src/types.ts
index 1451c7f..5fca4b8 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -23,6 +23,13 @@ export interface Series {
 	position: number;
 }
 
+function isbn(len: number) {
+	return z.preprocess(
+		val => (typeof val === "string" ? val.replace(/[\s-]+/g, "") : val),
+		z.string().length(len).nullable()
+	);
+}
+
 export const bookSchema = z.object({
 	title: z.string(),
 	subtitle: z.string(),
@@ -30,16 +37,12 @@ export const bookSchema = z.object({
 	authors: z.array(authorSchema),
 	series: seriesSchema.nullable(),
 	publisher: z.string(),
-	publishedAt: z.date(),
+	publishedAt: z.coerce.date(),
 	genres: z.array(z.string()),
 	coverImageUrl: z.url(),
 	pageCount: z.number().min(0),
-	isbn: z.string()
-		.transform(val => val.replace(/-+/g, ''))
-		.pipe(z.string().length(10)),
-	isbn13: z.string()
-		.transform(val => val.replace(/-+/g, ''))
-		.pipe(z.string().length(10)),
+	isbn: isbn(10),
+	isbn13: isbn(13),
 });
 
 export type Book = z.infer<typeof bookSchema>;