diff --git a/sasbook/Gemfile.lock b/sasbook/Gemfile.lock
index 5b38263..62ec1b3 100644
--- a/sasbook/Gemfile.lock
+++ b/sasbook/Gemfile.lock
@@ -1,8 +1,8 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
     backports (3.15.0)
     colorator (1.1.0)
     concurrent-ruby (1.1.5)
@@ -57,7 +57,7 @@ GEM
     multi_json (1.14.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (4.0.1)
+    public_suffix (5.0.0)
     rack (1.6.11)
     rack-protection (1.5.5)
       rack