diff --git a/Chapter02/pichat-api-attachments-service/Gemfile.lock b/Chapter02/pichat-api-attachments-service/Gemfile.lock
index e7997df..09e40ce 100644
--- a/Chapter02/pichat-api-attachments-service/Gemfile.lock
+++ b/Chapter02/pichat-api-attachments-service/Gemfile.lock
@@ -43,7 +43,7 @@ GEM
     builder (3.2.3)
     byebug (9.1.0)
     concurrent-ruby (1.0.5)
-    crass (1.0.2)
+    crass (1.0.5)
     database_cleaner (1.6.2)
     diff-lcs (1.3)
     erubi (1.7.0)
@@ -80,7 +80,7 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
-    loofah (2.1.1)
+    loofah (2.3.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.6.6)
@@ -89,12 +89,12 @@ GEM
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     minitest (5.10.3)
     multi_json (1.12.2)
     nio4r (2.1.0)
-    nokogiri (1.8.1)
-      mini_portile2 (~> 2.3.0)
+    nokogiri (1.10.5)
+      mini_portile2 (~> 2.4.0)
     puma (3.10.0)
     rack (2.0.3)
     rack-test (0.7.0)