diff --git a/gemfiles/ar_5.1.gemfile b/gemfiles/ar_5.1.gemfile
index dbdfa716..c822d943 100644
--- a/gemfiles/ar_5.1.gemfile
+++ b/gemfiles/ar_5.1.gemfile
@@ -4,8 +4,5 @@ source "https://rubygems.org"
 
 gem "activerecord", [">= 5.1.6.2", "< 5.2"]
 gem "rails-controller-testing", "~> 1.0.2"
-gem "mysql2", "~> 0.5.2"
-gem "pg", "~> 1.1"
-gem "sqlite3", "~> 1.4"
 
 gemspec path: "../"
diff --git a/gemfiles/ar_5.2.gemfile b/gemfiles/ar_5.2.gemfile
index a08770fa..28238464 100644
--- a/gemfiles/ar_5.2.gemfile
+++ b/gemfiles/ar_5.2.gemfile
@@ -4,8 +4,5 @@ source "https://rubygems.org"
 
 gem "activerecord", [">= 5.2.2.1", "< 5.3"]
 gem "rails-controller-testing", "~> 1.0.2"
-gem "mysql2", "~> 0.5.2"
-gem "pg", "~> 1.1"
-gem "sqlite3", "~> 1.4"
 
 gemspec path: "../"
diff --git a/gemfiles/ar_6.0.gemfile b/gemfiles/ar_6.0.gemfile
index c68e850b..5885632b 100644
--- a/gemfiles/ar_6.0.gemfile
+++ b/gemfiles/ar_6.0.gemfile
@@ -4,8 +4,5 @@ source "https://rubygems.org"
 
 gem "activerecord", ["6.0.0"]
 gem "rails-controller-testing", "~> 1.0.3"
-gem "mysql2", "~> 0.5.2"
-gem "pg", "~> 1.1"
-gem "sqlite3", "~> 1.4"
 
 gemspec path: "../"