diff --git a/actiontext/test/template/form_helper_test.rb b/actiontext/test/template/form_helper_test.rb
index 047f83af7d..c87d53fe3c 100644
--- a/actiontext/test/template/form_helper_test.rb
+++ b/actiontext/test/template/form_helper_test.rb
@@ -34,7 +34,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="content" id="trix_input_1" />' \
+        '<input type="hidden" name="content" id="trix_input_1" autocomplete="off" />' \
         '<trix-editor input="trix_input_1" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -48,7 +48,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" />' \
+        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" autocomplete="off" />' \
         '<trix-editor id="message_content" input="message_content_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -62,7 +62,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" />' \
+        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" autocomplete="off" />' \
         '<trix-editor id="message_content" input="message_content_trix_input_message" class="custom-class" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -76,7 +76,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[not_an_attribute]" id="message_not_an_attribute_trix_input_message" />' \
+        '<input type="hidden" name="message[not_an_attribute]" id="message_not_an_attribute_trix_input_message" autocomplete="off" />' \
         '<trix-editor id="message_not_an_attribute" input="message_not_an_attribute_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -90,7 +90,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[content]" id="trix_input_2" />' \
+        '<input type="hidden" name="message[content]" id="trix_input_2" autocomplete="off" />' \
         '<trix-editor id="message_content" input="trix_input_2" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -104,7 +104,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" />' \
+        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" autocomplete="off" />' \
         '<trix-editor placeholder="Content" id="message_content" input="message_content_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -120,7 +120,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[title]" id="message_title_trix_input_message" />' \
+        '<input type="hidden" name="message[title]" id="message_title_trix_input_message" autocomplete="off" />' \
         '<trix-editor placeholder="Story title" id="message_title" input="message_title_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -134,7 +134,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[title]" id="message_title_trix_input_message" value="&lt;h1&gt;hello world&lt;/h1&gt;" />' \
+        '<input type="hidden" name="message[title]" id="message_title_trix_input_message" value="&lt;h1&gt;hello world&lt;/h1&gt;" autocomplete="off" />' \
         '<trix-editor id="message_title" input="message_title_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -148,7 +148,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[title]" id="message_title_trix_input_message" form="other_form" />' \
+        '<input type="hidden" name="message[title]" id="message_title_trix_input_message" form="other_form" autocomplete="off" />' \
         '<trix-editor id="message_title" input="message_title_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -162,7 +162,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" />' \
+        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" autocomplete="off" />' \
         '<trix-editor id="message_content" input="message_content_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/direct_uploads" data-blob-url-template="http://test.host/rails/active_storage/blobs/redirect/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",
@@ -176,7 +176,7 @@ class ActionText::FormHelperTest < ActionView::TestCase
 
     assert_dom_equal \
       '<form action="/messages" accept-charset="UTF-8" method="post">' \
-        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" />' \
+        '<input type="hidden" name="message[content]" id="message_content_trix_input_message" autocomplete="off" />' \
         '<trix-editor id="message_content" input="message_content_trix_input_message" class="trix-content" data-direct-upload-url="http://test.host/rails/active_storage/direct_uploads" data-blob-url-template="http://test.host/blobs/:signed_id/:filename">' \
         "</trix-editor>" \
       "</form>",