diff --git a/.drone.yml b/.drone.yml
index 551ad3b..433c314 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -5,7 +5,7 @@ name: default
 
 steps:
   - name: build
-    image: ruby:latest
+    image: ruby:3.3.1
     commands:
       - gem update --system
       - gem install bundler
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..bea438e
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+3.3.1
diff --git a/Gemfile.lock b/Gemfile.lock
index 41dca83..6e20758 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -25,7 +25,8 @@ GEM
     eventmachine (1.2.7)
     ffi (1.16.3)
     forwardable-extended (2.6.0)
-    google-protobuf (3.25.3-x86_64-linux)
+    google-protobuf (4.26.1-x86_64-linux)
+      rake (>= 13)
     html-pipeline (2.14.3)
       activesupport (>= 2)
       nokogiri (>= 1.4)
@@ -80,7 +81,7 @@ GEM
     minitest (5.22.3)
     mutex_m (0.2.0)
     negarmoji (0.1.10)
-    nokogiri (1.15.6-x86_64-linux)
+    nokogiri (1.16.4-x86_64-linux)
       racc (~> 1.4)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
@@ -93,9 +94,8 @@ GEM
     rexml (3.2.6)
     rouge (4.2.1)
     safe_yaml (1.0.5)
-    sass-embedded (1.63.6)
-      google-protobuf (~> 3.23)
-      rake (>= 13.0.0)
+    sass-embedded (1.76.0-x86_64-linux-gnu)
+      google-protobuf (>= 3.25, < 5.0)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
     tzinfo (2.0.6)