diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 989178a3aca4f2a8d3d623d8f6ccc2166350cfd0..94817790159531a3d5f0d76020b3bc1d1fcf56a5 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-10
+  IMAGE_VER: 4.2.1-passenger-11
 
 services:
   - docker:19.03.12-dind
diff --git a/.gitmodules b/.gitmodules
index 8af12574f871d2271586af29c5d83f890d534f43..2682af9eb4fa97d15bdc9490c9ba1deaa757c93c 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -19,3 +19,6 @@
 [submodule "plugins/redmine_theme_changer"]
 	path = plugins/redmine_theme_changer
 	url = https://github.com/haru/redmine_theme_changer.git
+[submodule "plugins/redmine_work_time"]
+	path = plugins/redmine_work_time
+	url = https://github.com/tkusukawa/redmine_work_time.git
diff --git a/plugins/redmine_work_time b/plugins/redmine_work_time
new file mode 160000
index 0000000000000000000000000000000000000000..d30876f176e899dfe6d57ddfd7d024e7dffd1e39
--- /dev/null
+++ b/plugins/redmine_work_time
@@ -0,0 +1 @@
+Subproject commit d30876f176e899dfe6d57ddfd7d024e7dffd1e39