diff --git a/spec/system/ai_helper/ai_proofreading_spec.rb b/spec/system/ai_helper/ai_proofreading_spec.rb
index 96b17127..b2e00733 100644
--- a/spec/system/ai_helper/ai_proofreading_spec.rb
+++ b/spec/system/ai_helper/ai_proofreading_spec.rb
@@ -8,36 +8,42 @@ RSpec.describe "AI Composer Proofreading Features", type: :system, js: true do
   before do
     assign_fake_provider_to(:ai_helper_model)
     SiteSetting.ai_helper_enabled = true
+
+    # This needs to be done because the streaming suggestions for composer
+    # happen in a background job, which sends the MessageBus event to the client.
+    Jobs.run_immediately!
     sign_in(admin)
   end
 
   let(:composer) { PageObjects::Components::Composer.new }
+  let(:rich) { composer.rich_editor }
   let(:toasts) { PageObjects::Components::Toasts.new }
   let(:diff_modal) { PageObjects::Modals::DiffModal.new }
+  let(:keyboard_shortcut) { [PLATFORM_KEY_MODIFIER, :alt, "p"] }
 
   context "when triggering via keyboard shortcut" do
-    it "proofreads selected text using" do
-      skip("Message bus updates not appearing in tests")
+    it "proofreads selected text" do
       visit "/new-topic"
       composer.fill_content("hello worldd !")
 
       composer.select_range(6, 12)
 
       DiscourseAi::Completions::Llm.with_prepared_responses(["world"]) do
-        composer.composer_input.send_keys([PLATFORM_KEY_MODIFIER, :alt, "p"])
+        composer.composer_input.send_keys(keyboard_shortcut)
+        expect(diff_modal).to have_diff("worldd", "world")
         diff_modal.confirm_changes
         expect(composer.composer_input.value).to eq("hello world !")
       end
     end
 
     it "proofreads all text when nothing is selected" do
-      skip("Message bus updates not appearing in tests")
       visit "/new-topic"
       composer.fill_content("hello worrld")
 
       # Simulate AI response
       DiscourseAi::Completions::Llm.with_prepared_responses(["hello world"]) do
-        composer.composer_input.send_keys([PLATFORM_KEY_MODIFIER, :alt, "p"])
+        composer.composer_input.send_keys(keyboard_shortcut)
+        expect(diff_modal).to have_diff("worrld", "world")
         diff_modal.confirm_changes
         expect(composer.composer_input.value).to eq("hello world")
       end
@@ -48,9 +54,42 @@ RSpec.describe "AI Composer Proofreading Features", type: :system, js: true do
 
       # Simulate AI response
       DiscourseAi::Completions::Llm.with_prepared_responses(["hello world"]) do
-        composer.composer_input.send_keys([PLATFORM_KEY_MODIFIER, :alt, "p"])
+        composer.composer_input.send_keys(keyboard_shortcut)
         expect(toasts).to have_error(I18n.t("js.discourse_ai.ai_helper.no_content_error"))
       end
     end
+
+    context "when using rich text editor" do
+      before { SiteSetting.rich_editor = true }
+
+      it "proofreads selected text and replaces it" do
+        visit "/new-topic"
+        expect(composer).to be_opened
+        composer.toggle_rich_editor
+        composer.type_content("hello worldd !")
+
+        # NOTE: The rich text editor cannot use select_range on the page object since it is
+        # a contenteditable element. It would be hard to make this generic enough to put in
+        # the page object, maybe at some point in the future we can refactor this.
+        execute_script(<<~JS, text)
+          const composer = document.querySelector("#reply-control .d-editor-input");
+          const startNode = composer.firstChild.firstChild;
+          composer.focus();
+          const range = document.createRange();
+          range.setStart(startNode, 6);
+          range.setEnd(startNode, 12);
+          const selection = window.getSelection();
+          selection.removeAllRanges();
+          selection.addRange(range);
+        JS
+
+        DiscourseAi::Completions::Llm.with_prepared_responses(["world"]) do
+          composer.composer_input.send_keys(keyboard_shortcut)
+          expect(diff_modal).to have_diff("worldd", "world")
+          diff_modal.confirm_changes
+          expect(rich).to have_css("p", text: "hello world !")
+        end
+      end
+    end
   end
 end
diff --git a/spec/system/page_objects/modals/diff_modal.rb b/spec/system/page_objects/modals/diff_modal.rb
index e4faa486..4c6a5a27 100644
--- a/spec/system/page_objects/modals/diff_modal.rb
+++ b/spec/system/page_objects/modals/diff_modal.rb
@@ -22,6 +22,11 @@ module PageObjects
       def new_value
         find(".composer-ai-helper-modal__new-value").text
       end
+
+      def has_diff?(old_value, new_value)
+        has_css?(".inline-diff ins", text: new_value) &&
+          has_css?(".inline-diff del", text: old_value)
+      end
     end
   end
 end