diff --git a/.circleci/config.yml b/.circleci/config.yml
index 8141f90..d433369 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -58,6 +58,10 @@ workflows:
           project: bixby
           name: ruby2-6
           ruby_version: 2.6.9
+      - bundle_lint_test:
+          project: bixby
+          name: ruby2-5
+          ruby_version: 2.5.9
 
   nightly:
     triggers:
@@ -84,4 +88,7 @@ workflows:
           project: bixby
           name: ruby2-6
           ruby_version: 2.6.9
-
+      - bundle_lint_test:
+          project: bixby
+          name: ruby2-5
+          ruby_version: 2.5.9
diff --git a/bixby.gemspec b/bixby.gemspec
index 80f445e..2abe562 100644
--- a/bixby.gemspec
+++ b/bixby.gemspec
@@ -15,7 +15,7 @@ Gem::Specification.new do |spec|
   spec.version       = '5.0.0'
   spec.license       = 'Apache-2.0'
 
-  spec.required_ruby_version = '>= 2.6'
+  spec.required_ruby_version = '>= 2.5'
 
   spec.add_dependency 'rubocop', '1.28.2'
   spec.add_dependency 'rubocop-ast'