diff --git a/Gemfile.lock b/Gemfile.lock
index c1c8e53..402c099 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -29,8 +29,8 @@ GEM
     ethon (0.14.0)
       ffi (>= 1.15.0)
     ffi (1.15.3)
-    gepub (1.0.14)
-      nokogiri (>= 1.8.2, < 1.13)
+    gepub (1.0.15)
+      nokogiri (>= 1.8.2, < 2.0)
       rubyzip (> 1.1.1, < 2.4)
     hashery (2.1.2)
     html-proofer (3.19.2)
@@ -49,9 +49,9 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2021.0704)
-    mini_portile2 (2.6.1)
-    nokogiri (1.12.3)
-      mini_portile2 (~> 2.6.1)
+    mini_portile2 (2.8.1)
+    nokogiri (1.14.3)
+      mini_portile2 (~> 2.8.0)
       racc (~> 1.4)
     nokogumbo (2.0.5)
       nokogiri (~> 1.8, >= 1.8.4)
@@ -80,7 +80,7 @@ GEM
       prawn (~> 2.2)
     public_suffix (4.0.6)
     pygments.rb (2.2.0)
-    racc (1.5.2)
+    racc (1.6.2)
     rainbow (3.0.0)
     rake (13.0.6)
     rexml (3.2.5)