diff --git a/.rubocop.yml b/.rubocop.yml
index 84f92b5c9..828e2e884 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -6,7 +6,7 @@ Rails:
   Enabled: true
 
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.5
   TargetRailsVersion: 5.2
   Include:
     - '**/*.ruby'
diff --git a/.travis.yml b/.travis.yml
index 43ed50c7e..0480e2d4b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,19 +2,13 @@ language: ruby
 sudo: required
 cache: bundler
 rvm:
-  - 2.6.3
-  - 2.4.6
-  - 2.3.8
+  - 2.6
+  - 2.5
 gemfile:
   - Gemfile
 services:
   - mysql
   - postgresql
-branches:
-  only:
-    - devel
-    - /^fix_.*$/
-    - /^feat_.*$/
 env:
   global:
     - REDMINE_LANG=en