diff --git a/activerecord/lib/active_record/associations/builder/association.rb b/activerecord/lib/active_record/associations/builder/association.rb
index 3b4b2431486172739d1a698c112c28ba7aa584ac..0c61094d6c7688bcc324b5692dba7c7c1465ae2f 100644
--- a/activerecord/lib/active_record/associations/builder/association.rb
+++ b/activerecord/lib/active_record/associations/builder/association.rb
@@ -128,5 +128,9 @@ def self.add_destroy_callbacks(model, reflection)
       name = reflection.name
       model.before_destroy lambda { |o| o.association(name).handle_dependency }
     end
+
+    private_class_method :build_scope, :macro, :valid_options, :validate_options, :define_extensions,
+      :define_callbacks, :define_accessors, :define_readers, :define_writers, :define_validations,
+      :valid_dependent_options, :check_dependent_options, :add_destroy_callbacks
   end
 end
diff --git a/activerecord/lib/active_record/associations/builder/belongs_to.rb b/activerecord/lib/active_record/associations/builder/belongs_to.rb
index fc00f1e900d7790cdd41027cb9ee433c79916d8a..03da67f73e81bef09d78aec780c04f1b754078a1 100644
--- a/activerecord/lib/active_record/associations/builder/belongs_to.rb
+++ b/activerecord/lib/active_record/associations/builder/belongs_to.rb
@@ -123,5 +123,8 @@ def self.define_validations(model, reflection)
         model.validates_presence_of reflection.name, message: :required
       end
     end
+
+    private_class_method :macro, :valid_options, :valid_dependent_options, :define_callbacks, :define_validations,
+      :add_counter_cache_callbacks, :add_touch_callbacks, :add_default_callbacks, :add_destroy_callbacks
   end
 end
diff --git a/activerecord/lib/active_record/associations/builder/collection_association.rb b/activerecord/lib/active_record/associations/builder/collection_association.rb
index 9fccfcce0c17312cbccbbac918ae05e47f2d0b2f..e53665ce822ba0421f7575aa8b2ce5186f2b863d 100644
--- a/activerecord/lib/active_record/associations/builder/collection_association.rb
+++ b/activerecord/lib/active_record/associations/builder/collection_association.rb
@@ -66,5 +66,7 @@ def #{name.to_s.singularize}_ids=(ids)
         end
       CODE
     end
+
+    private_class_method :valid_options, :define_callback, :define_extensions, :define_readers, :define_writers
   end
 end
diff --git a/activerecord/lib/active_record/associations/builder/has_many.rb b/activerecord/lib/active_record/associations/builder/has_many.rb
index 5b9617bc6d87ac4e249c022ffeeb639dbcba7e69..556e2988f5ec6f67dd0a2ffb0480074b15a1886e 100644
--- a/activerecord/lib/active_record/associations/builder/has_many.rb
+++ b/activerecord/lib/active_record/associations/builder/has_many.rb
@@ -13,5 +13,7 @@ def self.valid_options(options)
     def self.valid_dependent_options
       [:destroy, :delete_all, :nullify, :restrict_with_error, :restrict_with_exception]
     end
+
+    private_class_method :macro, :valid_options, :valid_dependent_options
   end
 end
diff --git a/activerecord/lib/active_record/associations/builder/has_one.rb b/activerecord/lib/active_record/associations/builder/has_one.rb
index bfb37d6eeeb30fcc35d093cbd45625a1f275c2d5..a17cfcb8058a4e77383bdac6e8111907f2af6ac9 100644
--- a/activerecord/lib/active_record/associations/builder/has_one.rb
+++ b/activerecord/lib/active_record/associations/builder/has_one.rb
@@ -26,5 +26,7 @@ def self.define_validations(model, reflection)
         model.validates_presence_of reflection.name, message: :required
       end
     end
+
+    private_class_method :macro, :valid_options, :valid_dependent_options, :add_destroy_callbacks, :define_validations
   end
 end
diff --git a/activerecord/lib/active_record/associations/builder/singular_association.rb b/activerecord/lib/active_record/associations/builder/singular_association.rb
index 0a02ef4cc119fcea235a55ea29e24a06e41d9a3e..0e22563b41fa7f0528b47c21e461ec5f9553985b 100644
--- a/activerecord/lib/active_record/associations/builder/singular_association.rb
+++ b/activerecord/lib/active_record/associations/builder/singular_association.rb
@@ -38,5 +38,7 @@ def create_#{name}!(*args, &block)
         end
       CODE
     end
+
+    private_class_method :valid_options, :define_accessors, :define_constructors
   end
 end
diff --git a/activerecord/test/cases/associations/extension_test.rb b/activerecord/test/cases/associations/extension_test.rb
index aef8f311120de861bd6461ed6cb25009a8374d3b..d93d787f7ce66d76f90f236b5846d3e4cc15dfc3 100644
--- a/activerecord/test/cases/associations/extension_test.rb
+++ b/activerecord/test/cases/associations/extension_test.rb
@@ -89,6 +89,6 @@ def test_association_with_default_scope
   private
 
     def extend!(model)
-      ActiveRecord::Associations::Builder::HasMany.define_extensions(model, :association_name) { }
+      ActiveRecord::Associations::Builder::HasMany.send(:define_extensions, model, :association_name) { }
     end
 end