diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index c47e0dc03c..6d2f75a3ae 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -13,34 +13,37 @@ module ActiveRecord
       class_attribute :aggregate_reflections, instance_writer: false, default: {}
     end
 
-    def self.create(macro, name, scope, options, ar)
-      reflection = reflection_class_for(macro).new(name, scope, options, ar)
-      options[:through] ? ThroughReflection.new(reflection) : reflection
-    end
-
-    def self.reflection_class_for(macro)
-      case macro
-      when :composed_of
-        AggregateReflection
-      when :has_many
-        HasManyReflection
-      when :has_one
-        HasOneReflection
-      when :belongs_to
-        BelongsToReflection
-      else
-        raise "Unsupported Macro: #{macro}"
+    class << self
+      def create(macro, name, scope, options, ar)
+        reflection = reflection_class_for(macro).new(name, scope, options, ar)
+        options[:through] ? ThroughReflection.new(reflection) : reflection
       end
-    end
 
-    def self.add_reflection(ar, name, reflection)
-      ar.clear_reflections_cache
-      name = name.to_s
-      ar._reflections = ar._reflections.except(name).merge!(name => reflection)
-    end
+      def add_reflection(ar, name, reflection)
+        ar.clear_reflections_cache
+        name = name.to_s
+        ar._reflections = ar._reflections.except(name).merge!(name => reflection)
+      end
 
-    def self.add_aggregate_reflection(ar, name, reflection)
-      ar.aggregate_reflections = ar.aggregate_reflections.merge(name.to_s => reflection)
+      def add_aggregate_reflection(ar, name, reflection)
+        ar.aggregate_reflections = ar.aggregate_reflections.merge(name.to_s => reflection)
+      end
+
+      private
+        def reflection_class_for(macro)
+          case macro
+          when :composed_of
+            AggregateReflection
+          when :has_many
+            HasManyReflection
+          when :has_one
+            HasOneReflection
+          when :belongs_to
+            BelongsToReflection
+          else
+            raise "Unsupported Macro: #{macro}"
+          end
+        end
     end
 
     # \Reflection enables the ability to examine the associations and aggregations of
diff --git a/activestorage/lib/active_storage/reflection.rb b/activestorage/lib/active_storage/reflection.rb
index 9074b20126..04a1b20882 100644
--- a/activestorage/lib/active_storage/reflection.rb
+++ b/activestorage/lib/active_storage/reflection.rb
@@ -18,21 +18,22 @@ module ActiveStorage
       end
     end
 
-    module ReflectionExtension
-      def reflection_class_for(macro)
-        case macro
-        when :has_one_attached
-          HasOneAttachedReflection
-        when :has_many_attached
-          HasManyAttachedReflection
-        else
-          super
-        end
-      end
-
+    module ReflectionExtension # :nodoc:
       def add_attachment_reflection(ar, name, reflection)
         ar.attachment_reflections.merge!(name.to_s => reflection)
       end
+
+      private
+        def reflection_class_for(macro)
+          case macro
+          when :has_one_attached
+            HasOneAttachedReflection
+          when :has_many_attached
+            HasManyAttachedReflection
+          else
+            super
+          end
+        end
     end
 
     module ActiveRecordExtensions