diff --git a/Gemfile b/Gemfile
index 30d05b9..e8dfa0c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,10 +2,12 @@
 
 source "https://rubygems.org"
 
+gem "jekyll", "~> 4.3"
 gem "jekyll-toc", "~> 0.17.1"
-gem "jekyll", "~> 4.2"
 gem "kramdown-math-katex", "~> 1.0"
-gem "rouge", "~> 3.27"
+gem "rouge", "~> 4.0"
 gem "webrick", "~> 1.7"
-gem "image_optim", "~> 0.25"
-gem "image_optim_pack", "~> 0.5.1"
+gem "image_optim", "~> 0.31.2"
+gem "image_optim_pack", "~> 0.9.1"
+# Currently required to fix incompatibility between Psych 4 and Ruby 3
+gem 'psych', '< 4'