diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a125179acbdfa994b7d9fde8de831da730c65fe4..989178a3aca4f2a8d3d623d8f6ccc2166350cfd0 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2,7 +2,7 @@ image: docker:19.03.12
 
 variables:
   DOCKER_TLS_CERTDIR: "/certs"
-  IMAGE_VER: 4.2.1-passenger-9
+  IMAGE_VER: 4.2.1-passenger-10
 
 services:
   - docker:19.03.12-dind
diff --git a/.gitmodules b/.gitmodules
index 2cd0db5ab77318011c8f9bd8b0391f5b3e3ab21a..8af12574f871d2271586af29c5d83f890d534f43 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -16,3 +16,6 @@
 [submodule "plugins/redmine-signals-plugin"]
 	path = plugins/traffic_lights
 	url = https://gitlab.pirati.cz/sperling/redmine-signals-plugin.git
+[submodule "plugins/redmine_theme_changer"]
+	path = plugins/redmine_theme_changer
+	url = https://github.com/haru/redmine_theme_changer.git
diff --git a/plugins/redmine_theme_changer b/plugins/redmine_theme_changer
new file mode 160000
index 0000000000000000000000000000000000000000..30247a1f11ed12104d36b9ed77cea128f364a1d0
--- /dev/null
+++ b/plugins/redmine_theme_changer
@@ -0,0 +1 @@
+Subproject commit 30247a1f11ed12104d36b9ed77cea128f364a1d0