diff --git a/webapp/ruby/Dockerfile b/webapp/ruby/Dockerfile
index 68018c9aa..9475329fe 100644
--- a/webapp/ruby/Dockerfile
+++ b/webapp/ruby/Dockerfile
@@ -1,6 +1,6 @@
 #syntax=docker/dockerfile:1
 
-FROM ruby:3.3-slim
+FROM ruby:3.4-slim
 
 RUN \
   --mount=type=cache,target=/var/lib/apt,sharing=locked \
diff --git a/webapp/ruby/Gemfile b/webapp/ruby/Gemfile
index 93240fae3..adad09112 100644
--- a/webapp/ruby/Gemfile
+++ b/webapp/ruby/Gemfile
@@ -4,6 +4,7 @@ gem 'puma'
 gem 'sinatra'
 gem 'mysql2'
 gem 'mysql2-cs-bind'
+gem 'bigdecimal'
 gem 'bcrypt'
 gem 'rackup'
 
diff --git a/webapp/ruby/Gemfile.lock b/webapp/ruby/Gemfile.lock
index 9d0ece7ba..624c36ac9 100644
--- a/webapp/ruby/Gemfile.lock
+++ b/webapp/ruby/Gemfile.lock
@@ -3,6 +3,7 @@ GEM
   specs:
     base64 (0.2.0)
     bcrypt (3.1.20)
+    bigdecimal (3.1.9)
     logger (1.6.1)
     multi_json (1.15.0)
     mustermann (3.0.3)
@@ -43,6 +44,7 @@ PLATFORMS
 
 DEPENDENCIES
   bcrypt
+  bigdecimal
   mysql2
   mysql2-cs-bind
   puma