diff --git a/src/main/java/org/ntlab/citrusserver/repositories/BookManager.java b/src/main/java/org/ntlab/citrusserver/repositories/BookManager.java
index cadd0f9..fad0974 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/BookManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/BookManager.java
@@ -2,15 +2,17 @@
 
 import org.ntlab.citrusserver.entities.Account;
 import org.ntlab.citrusserver.entities.Book;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Repository;
 import java.util.HashMap;
 
 @Repository
 public class BookManager {
 
-    private HashMap<String, HashMap<Integer, Book>> booksMap = new HashMap<>();
+    private final HashMap<String, HashMap<Integer, Book>> booksMap = new HashMap<>();
     private final AccountManager accountManager; //仮
 
+    @Autowired
     public BookManager(AccountManager accountManager) {
         this.accountManager = accountManager;
     }