diff --git a/config/initializers/premailer.rb b/config/initializers/premailer.rb
index ad80d80f0797cbcc779cab91e05c8d969fe4d7c9..687f56eb884a0e7760bfbee12747dcacb6a63ba5 100644
--- a/config/initializers/premailer.rb
+++ b/config/initializers/premailer.rb
@@ -7,6 +7,5 @@
   remove_comments: true,
   remove_ids: false,
   remove_scripts: false,
-  output_encoding: 'US-ASCII',
   strategies: ::Rails.env.production? ? [:asset_pipeline] : [:asset_pipeline, :network]
 )
diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index 9dcb0cdf103e2ffedb820dcfda32b357c362d147..f845a39735120b2f19be17fc4262b8f3c655df8a 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -89,16 +89,16 @@
     end
   end
 
-  describe 'with HTML-encoded entities' do
+  describe 'with non-ASCII characters' do
     before do
-      described_class.test_email('test@test.com', 'Subject', 'Some body with —').deliver
+      described_class.test_email('test@test.com', 'Subject', 'Some body with 中文 —').deliver
     end
 
     subject { ActionMailer::Base.deliveries.last }
 
-    it 'retains 7bit encoding' do
-      expect(subject.body.ascii_only?).to eq(true)
-      expect(subject.body.encoding).to eq('7bit')
+    it 'removes HTML encoding and uses UTF-8 charset' do
+      expect(subject.charset).to eq('UTF-8')
+      expect(subject.body).to include('中文 —')
     end
   end