diff --git a/Gemfile.lock b/Gemfile.lock
index 2236ff7..e43869b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,8 +2,8 @@ GEM
   remote: https://rubygems.org/
   specs:
     Ascii85 (1.0.3)
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
     afm (0.2.2)
     asciidoctor (2.0.10)
     asciidoctor-diagram (1.5.18)
@@ -53,7 +53,7 @@ GEM
     prawn-templates (0.1.1)
       pdf-reader (~> 2.0)
       prawn (~> 2.2)
-    public_suffix (4.0.1)
+    public_suffix (5.0.0)
     pygments.rb (1.2.1)
       multi_json (>= 1.0.0)
     rouge (3.11.1)