diff --git a/Chapter02/pichat-api-attachments-service/Gemfile.lock b/Chapter02/pichat-api-attachments-service/Gemfile.lock
index e7997df..9262ccd 100644
--- a/Chapter02/pichat-api-attachments-service/Gemfile.lock
+++ b/Chapter02/pichat-api-attachments-service/Gemfile.lock
@@ -161,7 +161,7 @@ GEM
     sqlite3 (1.3.13)
     thor (0.20.0)
     thread_safe (0.3.6)
-    tzinfo (1.2.4)
+    tzinfo (1.2.10)
       thread_safe (~> 0.1)
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)