diff --git a/hartl-rails/hello-app/Gemfile.lock b/hartl-rails/hello-app/Gemfile.lock
index f37777e5..e1e45df3 100644
--- a/hartl-rails/hello-app/Gemfile.lock
+++ b/hartl-rails/hello-app/Gemfile.lock
@@ -49,6 +49,7 @@ GEM
       execjs
     coffee-script-source (1.12.2)
     concurrent-ruby (1.0.4)
+    crass (1.0.6)
     debug_inspector (0.0.2)
     erubis (2.7.0)
     execjs (2.7.0)
@@ -66,7 +67,8 @@ GEM
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    loofah (2.0.3)
+    loofah (2.19.1)
+      crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mail (2.6.4)
       mime-types (>= 1.16, < 4)
@@ -74,14 +76,16 @@ GEM
     mime-types (3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
-    mini_portile2 (2.1.0)
+    mini_portile2 (2.8.0)
     minitest (5.10.1)
     multi_json (1.12.1)
     nio4r (1.2.1)
-    nokogiri (1.7.0.1)
-      mini_portile2 (~> 2.1.0)
+    nokogiri (1.13.10)
+      mini_portile2 (~> 2.8.0)
+      racc (~> 1.4)
     pg (0.18.4)
     puma (3.4.0)
+    racc (1.6.1)
     rack (2.0.1)
     rack-test (0.6.3)
       rack (>= 1.0)