diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a11c4705e82b249992772e575864c84a97a6ddb9..5d2fad03f190ff6c4746b0d2919298efd5ab3697 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,9 +1,8 @@
-image: "ruby:2.3.1"
+image: "dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.3-git-2.7-phantomjs-2.1"
 
 cache:
   key: "ruby-231"
   paths:
-  - vendor/apt
   - vendor/ruby
 
 variables:
@@ -141,14 +140,13 @@ spinach 9 10: *spinach-knapsack
 
 # Execute all testing suites against Ruby 2.1
 .ruby-21: &ruby-21
-  image: "ruby:2.1"
+  image: "dev.gitlab.org:5005/gitlab/gitlab-build-images:ruby-2.1-git-2.7-phantomjs-2.1"
   <<: *use-db
   only:
     - master
   cache:
     key: "ruby21"
     paths:
-      - vendor/apt
       - vendor/ruby
 
 .rspec-knapsack-ruby21: &rspec-knapsack-ruby21
diff --git a/CHANGELOG b/CHANGELOG
index 4c8d9bd5d73535bf5ba6a119f047dbab798acdad..3849683a35e8f19b42ffb96644f88403b05c1866 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -24,6 +24,7 @@ v 8.13.0 (unreleased)
   - Preserve label filters when sorting !6136 (Joseph Frazier)
   - Only update issuable labels if they have been changed
   - Take filters in account in issuable counters. !6496
+  - Use custom Ruby images to test builds (registry.dev.gitlab.org/gitlab/gitlab-build-images:*)
   - Revoke button in Applications Settings underlines on hover.
   - Add missing values to linter !6276 (Katarzyna Kobierska Ula Budziszewska)
   - Fix Long commit messages overflow viewport in file tree
diff --git a/scripts/prepare_build.sh b/scripts/prepare_build.sh
index 6e987e7d9c9167d12ce938f0e122437b48da819f..1eaafdce389866943317e01c6260b8b2250d7b58 100755
--- a/scripts/prepare_build.sh
+++ b/scripts/prepare_build.sh
@@ -16,21 +16,6 @@ retry() {
 }
 
 if [ -f /.dockerenv ] || [ -f ./dockerinit ]; then
-    mkdir -p vendor/apt
-
-    # Install phantomjs package
-    pushd vendor/apt
-    PHANTOMJS_FILE="phantomjs-$PHANTOMJS_VERSION-linux-x86_64"
-    if [ ! -d "$PHANTOMJS_FILE" ]; then
-        curl -q -L "https://s3.amazonaws.com/gitlab-build-helpers/$PHANTOMJS_FILE.tar.bz2" | tar jx
-    fi
-    cp "$PHANTOMJS_FILE/bin/phantomjs" "/usr/bin/"
-    popd
-
-    # Try to install packages
-    retry 'apt-get update -yqqq; apt-get -o dir::cache::archives="vendor/apt" install -y -qq --force-yes \
-      libicu-dev libkrb5-dev cmake nodejs postgresql-client mysql-client unzip'
-
     cp config/database.yml.mysql config/database.yml
     sed -i 's/username:.*/username: root/g' config/database.yml
     sed -i 's/password:.*/password:/g' config/database.yml