diff --git a/lib/active_record_encryption/encryptor/active_support.rb b/lib/active_record_encryption/encryptor/active_support.rb
index 7259380..bca0122 100644
--- a/lib/active_record_encryption/encryptor/active_support.rb
+++ b/lib/active_record_encryption/encryptor/active_support.rb
@@ -3,9 +3,9 @@
 module ActiveRecordEncryption
   module Encryptor
     class ActiveSupport < Raw
-      def initialize(key:, salt:)
+      def initialize(key:, salt:, cipher: nil)
         key_generator = ::ActiveSupport::KeyGenerator.new(key)
-        @encryptor = ::ActiveSupport::MessageEncryptor.new(key_generator.generate_key(salt, 32))
+        @encryptor = ::ActiveSupport::MessageEncryptor.new(key_generator.generate_key(salt, 32), cipher: cipher)
       end
 
       def encrypt(value)
diff --git a/spec/active_record_encryption/encryptor/active_support_spec.rb b/spec/active_record_encryption/encryptor/active_support_spec.rb
index b0fd46f..d826390 100644
--- a/spec/active_record_encryption/encryptor/active_support_spec.rb
+++ b/spec/active_record_encryption/encryptor/active_support_spec.rb
@@ -12,6 +12,30 @@
           expect { described_class.new(key: key) }.to raise_error(ArgumentError)
         end
       end
+
+      context 'with cipher' do
+        let(:instance) { described_class.new(salt: salt, key: key, cipher: cipher) }
+
+        def new_cipher
+          instance.instance_variable_get(:@encryptor).send(:new_cipher)
+        end
+
+        context 'cipher is "aes-256-gcm"' do
+          let(:cipher) { 'aes-256-gcm' }
+
+          it 'builds aes-256-gcm encryptor' do
+            expect(new_cipher.name).to eq('id-aes256-GCM')
+          end
+        end
+
+        context 'cipher is "aes-256-cbc"' do
+          let(:cipher) { 'aes-256-cbc' }
+
+          it 'builds aes-256-cbc encryptor' do
+            expect(new_cipher.name).to eq('AES-256-CBC')
+          end
+        end
+      end
     end
 
     describe '#encrypt/decrypt' do