diff --git a/.github/workflows/push.yml b/.github/workflows/push.yml
index 952d556..84460da 100644
--- a/.github/workflows/push.yml
+++ b/.github/workflows/push.yml
@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['3.0', '3.1', '3.2', '3.3']
+        ruby: ['3.0', '3.1', '3.2', '3.3', '3.4']
 
     runs-on: ubuntu-latest
     name: Test against Ruby ${{ matrix.ruby }}
diff --git a/datev.gemspec b/datev.gemspec
index 86e6687..bbd17e7 100644
--- a/datev.gemspec
+++ b/datev.gemspec
@@ -21,6 +21,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 3.0'
 
   spec.add_development_dependency "bundler"
+  spec.add_development_dependency "csv"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "rspec"
   spec.add_development_dependency 'simplecov'