diff --git a/.rubocop.yml b/.rubocop.yml
index 3b2475caf0..d0930b8f6b 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -4,7 +4,7 @@ require:
   - rubocop-rails
 
 AllCops:
-  TargetRubyVersion: 2.5
+  TargetRubyVersion: 2.7
   # RuboCop has a bunch of cops enabled by default. This setting tells RuboCop
   # to ignore them, so only the ones explicitly set in this file are enabled.
   DisabledByDefault: true
diff --git a/railties/lib/rails/generators/migration.rb b/railties/lib/rails/generators/migration.rb
index e9e681e1fb..cdf94d426e 100644
--- a/railties/lib/rails/generators/migration.rb
+++ b/railties/lib/rails/generators/migration.rb
@@ -63,11 +63,7 @@ module Rails
         numbered_destination = File.join(dir, ["%migration_number%", base].join("_"))
 
         file = create_migration numbered_destination, nil, config do
-          if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
-            ERB.new(::File.binread(source), trim_mode: "-", eoutvar: "@output_buffer").result(context)
-          else
-            ERB.new(::File.binread(source), nil, "-", "@output_buffer").result(context)
-          end
+          ERB.new(::File.binread(source), trim_mode: "-", eoutvar: "@output_buffer").result(context)
         end
         Rails::Generators.add_generated_file(file)
       end
diff --git a/railties/test/generators/generators_test_helper.rb b/railties/test/generators/generators_test_helper.rb
index d7766e3112..2d56b90a80 100644
--- a/railties/test/generators/generators_test_helper.rb
+++ b/railties/test/generators/generators_test_helper.rb
@@ -80,11 +80,7 @@ module GeneratorsTestHelper
   end
 
   def evaluate_template(file, locals = {})
-    erb = if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
-      ERB.new(File.read(file), trim_mode: "-", eoutvar: "@output_buffer")
-    else
-      ERB.new(File.read(file), nil, "-", "@output_buffer")
-    end
+    erb = ERB.new(File.read(file), trim_mode: "-", eoutvar: "@output_buffer")
     context = Class.new do
       locals.each do |local, value|
         class_attribute local, default: value