diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6bea4457f2..4327fe890c 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -11,7 +11,7 @@ executors:
       - image: cimg/base:2020.01
   linting-executor:
     docker:
-      - image: cimg/ruby:3.3.6-browsers
+      - image: cimg/ruby:3.4.1-browsers
         environment:
           RAILS_ENV: test
           TZ: "Europe/London"
@@ -28,7 +28,7 @@ executors:
     resource_class: small
   test-executor:
     docker:
-      - image: ministryofjustice/apply-ci:latest-3.3.6
+      - image: ministryofjustice/apply-ci:latest-3.4.1
         environment:
           RAILS_ENV: test
           NODE_OPTIONS: --openssl-legacy-provider
@@ -94,22 +94,22 @@ references:
   restore_gems_cache: &restore_gems_cache
     restore_cache:
       keys:
-        - v3.3.6-gems-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "Gemfile.lock" }}
+        - v3.4.1-gems-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "Gemfile.lock" }}
 
   restore_js_packages_cache: &restore_js_packages_cache
     restore_cache:
       keys:
-        - v3.3.6-yarn-packages-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "yarn.lock" }}
+        - v3.4.1-yarn-packages-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "yarn.lock" }}
 
   save_gems_cache: &save_gems_cache
     save_cache:
-        key: v3.3.6-gems-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "Gemfile.lock" }}
+        key: v3.4.1-gems-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "Gemfile.lock" }}
         paths:
           - vendor/bundle
 
   save_js_packages_cache: &save_js_packages_cache
     save_cache:
-      key: v3.3.6-yarn-packages-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "yarn.lock" }}
+      key: v3.4.1-yarn-packages-cache-{{ .Environment.CACHE_VERSION }}-{{ checksum "yarn.lock" }}
       paths:
         - node_modules
 
diff --git a/.ruby-version b/.ruby-version
index 9c25013dbb..47b322c971 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.3.6
+3.4.1
diff --git a/Dockerfile b/Dockerfile
index 6f9f29167c..7226b003a7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ministryofjustice/apply-base:latest-3.3.6
+FROM ministryofjustice/apply-base:latest-3.4.1
 LABEL org.opencontainers.image.authors="apply for legal aid team"
 
 # add non-root user and group with alpine first available uid, 1000
diff --git a/Gemfile.lock b/Gemfile.lock
index 336ebcdfed..64c69c1d18 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -170,6 +170,9 @@ GEM
     coderay (1.1.3)
     coercible (1.0.0)
       descendants_tracker (~> 0.0.1)
+    combine_pdf (1.0.29)
+      matrix
+      ruby-rc4 (>= 0.1.5)
     concurrent-ruby (1.3.4)
     connection_pool (2.4.1)
     cookiejar (0.3.4)
@@ -312,8 +315,9 @@ GEM
     govuk_notify_rails (3.0.0)
       notifications-ruby-client (~> 6.2)
       rails (>= 4.1.0)
-    grover (1.2.1)
-      nokogiri (~> 1)
+    grover (0.12.3)
+      combine_pdf (~> 1.0)
+      nokogiri (~> 1.0)
     guard (2.19.0)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
@@ -651,6 +655,7 @@ GEM
     ruby-graphviz (1.2.5)
       rexml
     ruby-progressbar (1.13.0)
+    ruby-rc4 (0.1.5)
     ruby-saml (1.17.0)
       nokogiri (>= 1.13.10)
       rexml
@@ -860,7 +865,7 @@ DEPENDENCIES
   webrick
 
 RUBY VERSION
-   ruby 3.3.6p108
+   ruby 3.4.1p0
 
 BUNDLED WITH
    2.6.2
diff --git a/docker/apply_base.dockerfile b/docker/apply_base.dockerfile
index fa02c2d38d..14a38b8461 100644
--- a/docker/apply_base.dockerfile
+++ b/docker/apply_base.dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:3.3.6-alpine3.21
+FROM ruby:3.4.1-alpine3.21
 LABEL org.opencontainers.image.authors="apply for legal aid team"
 
 # fail early and print all commands
diff --git a/docker/apply_ci.dockerfile b/docker/apply_ci.dockerfile
index 98c5f3bc7b..4bc3867335 100644
--- a/docker/apply_ci.dockerfile
+++ b/docker/apply_ci.dockerfile
@@ -1,4 +1,4 @@
-FROM cimg/ruby:3.3.6-browsers
+FROM cimg/ruby:3.4.1-browsers
 LABEL org.opencontainers.image.authors="apply for legal aid team"
 
 RUN wget https://mirrors.kernel.org/ubuntu/pool/main/libf/libffi/libffi6_3.2.1-8_amd64.deb -O /tmp/libffi6_3.2.1-8_amd64.deb