diff --git a/.travis.yml b/.travis.yml
index 012dc77d..47f092e6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -49,6 +49,9 @@ after_script:
   - bash -x ./test/ci/redmine_install.sh -u
 
 env:
+  - DB=sqlite   REDMINE_GIT_TAG=4.0-stable
+  - DB=mysql    REDMINE_GIT_TAG=4.0-stable
+  - DB=postgres REDMINE_GIT_TAG=4.0-stable
   - DB=sqlite   REDMINE_GIT_TAG=4.1-stable
   - DB=mysql    REDMINE_GIT_TAG=4.1-stable
   - DB=postgres REDMINE_GIT_TAG=4.1-stable
diff --git a/README.md b/README.md
index 9f14c2bd..6f411133 100644
--- a/README.md
+++ b/README.md
@@ -36,12 +36,12 @@ Features
   * Documents and folders symbolic links  
   * Trash bin
   * Documents attachable to issues
-  * Compatible with Redmine 4.1.x
+  * Compatible with Redmine 4.0.x and 4.1.x
 
 Dependencies
 ------------
   
-  * Redmine 4.1.0 or higher
+  * Redmine 4.0.0 or higher
 
 ### Full-text search (optional)
 
diff --git a/init.rb b/init.rb
index c3ae7d8a..c329ec42 100644
--- a/init.rb
+++ b/init.rb
@@ -35,7 +35,7 @@ Redmine::Plugin.register :redmine_dmsf do
   description 'Document Management System Features'
   version '2.4.3'
   
-  requires_redmine version_or_higher: '4.1.0'
+  requires_redmine version_or_higher: '4.0.0'
 
   settings partial: 'settings/dmsf_settings',
             default: {