diff --git a/app/models/devise_token_auth/concerns/active_record_support.rb b/app/models/devise_token_auth/concerns/active_record_support.rb
index 54d2e71b2..d086b8bdc 100644
--- a/app/models/devise_token_auth/concerns/active_record_support.rb
+++ b/app/models/devise_token_auth/concerns/active_record_support.rb
@@ -4,7 +4,7 @@ module DeviseTokenAuth::Concerns::ActiveRecordSupport
   extend ActiveSupport::Concern
 
   included do
-    serialize :tokens, DeviseTokenAuth::TokensSerialization
+    serialize :tokens, DeviseTokenAuth::Concerns::TokensSerialization
   end
 
   class_methods do
diff --git a/app/models/devise_token_auth/concerns/tokens_serialization.rb b/app/models/devise_token_auth/concerns/tokens_serialization.rb
index 0f8dfd7d4..5e6cc1c6d 100644
--- a/app/models/devise_token_auth/concerns/tokens_serialization.rb
+++ b/app/models/devise_token_auth/concerns/tokens_serialization.rb
@@ -1,4 +1,4 @@
-module DeviseTokenAuth::TokensSerialization
+module DeviseTokenAuth::Concerns::TokensSerialization
   # Serialization hash to json
   def self.dump(object)
     object.each_value(&:compact!) unless object.nil?
diff --git a/devise_token_auth.gemspec b/devise_token_auth.gemspec
index a4cad9e89..5fc494465 100644
--- a/devise_token_auth.gemspec
+++ b/devise_token_auth.gemspec
@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
   s.required_ruby_version = ">= 2.2.0"
 
   s.add_dependency 'rails', '>= 4.2.0', '< 6.1'
-  s.add_dependency 'devise', '> 3.5.2', '< 4.7'
+  s.add_dependency 'devise', '> 3.5.2', '< 5'
   s.add_dependency 'bcrypt', '~> 3.0'
 
   s.add_development_dependency 'appraisal'
diff --git a/test/models/concerns/tokens_serialization_test.rb b/test/models/concerns/tokens_serialization_test.rb
index e99a6690a..388ec4c86 100644
--- a/test/models/concerns/tokens_serialization_test.rb
+++ b/test/models/concerns/tokens_serialization_test.rb
@@ -1,8 +1,8 @@
 require 'test_helper'
 
 if DEVISE_TOKEN_AUTH_ORM == :active_record
-  describe 'DeviseTokenAuth::TokensSerialization' do
-    let(:ts) { DeviseTokenAuth::TokensSerialization }
+  describe 'DeviseTokenAuth::Concerns::TokensSerialization' do
+    let(:ts) { DeviseTokenAuth::Concerns::TokensSerialization }
     let(:user) { FactoryBot.create(:user) }
     let(:tokens) do
       # Сreate all possible token's attributes combinations