diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a2b67ca..761f9e2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -29,10 +29,12 @@ before_script:
 
 ruby-2.1-git-2.7-phantomjs-2.1 test: *test_build
 ruby-2.3-git-2.7-phantomjs-2.1 test: *test_build
+ruby-2.3-static-analyses test: *test_build
 www-gitlab-com test: *test_build
 doc-gitlab-com test: *test_build
 
 ruby-2.1-git-2.7-phantomjs-2.1: *build_and_deploy
 ruby-2.3-git-2.7-phantomjs-2.1: *build_and_deploy
+ruby-2.3-static-analyses: *build_and_deploy
 www-gitlab-com: *build_and_deploy
 doc-gitlab-com: *build_and_deploy
diff --git a/Dockerfile.ruby-2.3-static-analyses b/Dockerfile.ruby-2.3-static-analyses
new file mode 100644
index 0000000..e110287
--- /dev/null
+++ b/Dockerfile.ruby-2.3-static-analyses
@@ -0,0 +1,3 @@
+FROM ruby:2.3-alpine
+
+RUN gem install knapsack