diff --git a/actionmailer/test/mail_service_test.rb b/actionmailer/test/mail_service_test.rb
index aa68cb466f6626cbd29ee601fed4e1441724a58d..6e0d727abdbc6223ab9e5e91e6333f72935e5b96 100755
--- a/actionmailer/test/mail_service_test.rb
+++ b/actionmailer/test/mail_service_test.rb
@@ -686,23 +686,23 @@ def test_explicitly_multipart_with_invalid_content_type
 
   def test_implicitly_multipart_messages
     mail = TestMailer.create_implicitly_multipart_example(@recipient)
-    assert_equal 3, mail.parts.length
+    assert_equal 6, mail.parts.length
     assert_equal "1.0", mail.mime_version
     assert_equal "multipart/alternative", mail.content_type
     assert_equal "text/yaml", mail.parts[0].content_type
     assert_equal "utf-8", mail.parts[0].sub_header("content-type", "charset")
-    assert_equal "text/plain", mail.parts[1].content_type
-    assert_equal "utf-8", mail.parts[1].sub_header("content-type", "charset")
-    assert_equal "text/html", mail.parts[2].content_type
+    assert_equal "text/plain", mail.parts[2].content_type
     assert_equal "utf-8", mail.parts[2].sub_header("content-type", "charset")
+    assert_equal "text/html", mail.parts[4].content_type
+    assert_equal "utf-8", mail.parts[4].sub_header("content-type", "charset")
   end
 
   def test_implicitly_multipart_messages_with_custom_order
     mail = TestMailer.create_implicitly_multipart_example(@recipient, nil, ["text/yaml", "text/plain"])
-    assert_equal 3, mail.parts.length
+    assert_equal 6, mail.parts.length
     assert_equal "text/html", mail.parts[0].content_type
-    assert_equal "text/plain", mail.parts[1].content_type
-    assert_equal "text/yaml", mail.parts[2].content_type
+    assert_equal "text/plain", mail.parts[2].content_type
+    assert_equal "text/yaml", mail.parts[4].content_type
   end
 
   def test_implicitly_multipart_messages_with_charset