diff --git a/Gemfile.lock b/Gemfile.lock
index 667f28e..ffb83ee 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -43,8 +43,8 @@ GEM
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.6.0)
-      public_suffix (>= 2.0.2, < 4.0)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
     arel (6.0.4)
     ast (2.4.0)
     builder (3.2.3)
@@ -84,7 +84,7 @@ GEM
     premailer-rails (1.10.3)
       actionmailer (>= 3)
       premailer (~> 1.7, >= 1.7.9)
-    public_suffix (3.1.1)
+    public_suffix (5.0.0)
     rack (1.6.11)
     rack-test (0.6.3)
       rack (>= 1.0)