diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java
index 1661d24..19d4718 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/BookRepository.java
@@ -8,7 +8,8 @@ import org.springframework.data.repository.CrudRepository;
 
 public interface BookRepository extends CrudRepository<Book, Long> {
 
-	// Handles both INSERT and UPDATE queries
-	List<Book> findById(String title);
+	public List<Book> findById(String title);
+
+	public boolean existsByIsbn(String isbn);
 
 }
\ No newline at end of file
diff --git a/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java b/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java
index 43699e5..e818424 100644
--- a/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java
+++ b/bookstore/src/main/java/com/fjordtek/bookstore/model/CategoryRepository.java
@@ -8,6 +8,6 @@ import org.springframework.data.repository.CrudRepository;
 
 public interface CategoryRepository extends CrudRepository<Category, Long> {
 
-	List<Category> findByName(String name);
+	public List<Category> findByName(String name);
 
 }
\ No newline at end of file