diff --git a/Gemfile.lock b/Gemfile.lock
index 5ec4a2e..ed93b9d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,8 +7,8 @@ GEM
       minitest (~> 5.1)
       tzinfo (~> 1.1)
       zeitwerk (~> 2.2, >= 2.2.2)
-    addressable (2.7.0)
-      public_suffix (>= 2.0.2, < 5.0)
+    addressable (2.8.1)
+      public_suffix (>= 2.0.2, < 6.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
@@ -74,7 +74,7 @@ GEM
       jekyll-theme-time-machine (= 0.1.1)
       jekyll-titles-from-headings (= 0.5.3)
       jemoji (= 0.12.0)
-      kramdown (>= 2.3.1)
+      kramdown (= 2.3.1)
       kramdown-parser-gfm (= 1.1.0)
       liquid (= 4.0.3)
       mercenary (~> 0.3)
@@ -224,7 +224,7 @@ GEM
       sawyer (~> 0.8.0, >= 0.5.3)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
-    public_suffix (4.0.6)
+    public_suffix (4.0.7)
     racc (1.5.2)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)