diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6bddcc9acaf5bf3c177746888cc4e194d0d059c9..953f91834e93c92988fccfaa1cb294657f83301b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,10 +1,11 @@
 .ruby_before_script: &ruby_before_script
   before_script:
-    - bundle install
+    - export BUNDLE_PATH=$CI_PROJECT_DIR/.gems
+    - bundle install --jobs 2 --retry 3
 
-.ruby_25
+ruby_25:
   <<: *ruby_before_script
-  image: 2.5-alpine
+  image: ruby:2.5
   cache:
     key: ruby_25
     paths:
diff --git a/Gemfile.lock b/Gemfile.lock
index 82841b9b1b8b10bcb1bba45cf88715da8cef9293..78b76442b7091e60869437d4850921b14e80771d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -18,13 +18,13 @@ GEM
     coderay (1.1.2)
     concurrent-ruby (1.1.5)
     diff-lcs (1.3)
-    fabrication (2.20.1)
-    ffi (1.9.25)
+    fabrication (2.20.2)
+    ffi (1.11.1)
     formatador (0.2.5)
-    fuubar (2.3.2)
+    fuubar (2.4.1)
       rspec-core (~> 3.0)
       ruby-progressbar (~> 1.4)
-    guard (2.14.2)
+    guard (2.15.1)
       formatador (>= 0.2.4)
       listen (>= 2.7, < 4.0)
       lumberjack (>= 1.0.12, < 2.0)
@@ -45,42 +45,42 @@ GEM
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
     lumberjack (1.0.13)
-    method_source (0.9.0)
+    method_source (0.9.2)
     minitest (5.12.2)
     nenv (0.3.0)
-    notiffany (0.1.1)
+    notiffany (0.1.3)
       nenv (~> 0.1)
       shellany (~> 0.0)
-    pry (0.11.3)
+    pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    rake (12.3.1)
+    rake (13.0.0)
     rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rb-inotify (0.10.0)
+      ffi (~> 1.0)
     rspec (3.8.0)
       rspec-core (~> 3.8.0)
       rspec-expectations (~> 3.8.0)
       rspec-mocks (~> 3.8.0)
-    rspec-core (3.8.0)
+    rspec-core (3.8.2)
       rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.1)
+    rspec-expectations (3.8.4)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
-    rspec-mocks (3.8.0)
+    rspec-mocks (3.8.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
-    rspec-support (3.8.0)
-    ruby-progressbar (1.10.0)
+    rspec-support (3.8.2)
+    ruby-progressbar (1.10.1)
     ruby_dep (1.5.0)
     sequel (5.24.0)
     shellany (0.0.1)
     sqlite3 (1.4.1)
-    thor (0.20.0)
+    thor (0.20.3)
     thread_safe (0.3.6)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    yard (0.9.16)
+    yard (0.9.20)
     zeitwerk (2.1.10)
 
 PLATFORMS
diff --git a/roqua-csv_export.gemspec b/roqua-csv_export.gemspec
index 1772a1abe8c7764429b3029e9bbeb8a6b5139677..d6c03224d428806a4232176196494a377acddcdd 100644
--- a/roqua-csv_export.gemspec
+++ b/roqua-csv_export.gemspec
@@ -12,9 +12,8 @@ Gem::Specification.new do |gem|
   gem.email         = "henk.van.der.veen@gmail.com"
   gem.homepage      = "https://docs.roqua.net"
 
-  gem.files         = `git ls-files`.split($/)
-  gem.executables   = gem.files.grep(%r{^bin/}).map { |f| File.basename(f) }
-  gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
+
+  gem.files = Dir["{lib}/**/*"] + ["Rakefile", "README.md"]
   gem.require_paths = ['lib']
   gem.metadata["yard.run"] = "yri" # use "yard" to build full HTML docs.
 
diff --git a/spec/lib/roqua/csv_export_spec.rb b/spec/lib/roqua/csv_export_spec.rb
index ef1e00a6836d9b7a197515aa5c99ed86cadfc7bc..a8221374be99d0807dbe9649a07c1534724dce25 100644
--- a/spec/lib/roqua/csv_export_spec.rb
+++ b/spec/lib/roqua/csv_export_spec.rb
@@ -7,7 +7,7 @@ OUTPUT_PATH = RSPEC_ROOT_PATH.join('..', 'tmp', 'data_export') # constant, since
 describe Roqua::CsvExport do
   let(:version_dir) { OUTPUT_PATH.join("example_#{export_version_key}") }
   let(:version_questionnaire_file) { version_dir.join("#{version_questionnaire_key}_#{Time.now.strftime("%Y-%m-%d")}.csv") }
-  let(:csv) { CSV.parse(version_questionnaire_file.read, col_sep: ';', headers: true) }
+  let(:csv) { CSV.read(version_questionnaire_file, col_sep: ';', headers: true, encoding: 'UTF-8') }
   let(:version_questionnaire_key) { 'all_quests' }
   let(:export_version_key) { 'v201809' }