diff --git a/app/assets/javascripts/discourse/app/lib/plugin-api.js b/app/assets/javascripts/discourse/app/lib/plugin-api.js
index c11b398fcaf..6f2f1190a27 100644
--- a/app/assets/javascripts/discourse/app/lib/plugin-api.js
+++ b/app/assets/javascripts/discourse/app/lib/plugin-api.js
@@ -1654,8 +1654,17 @@ class PluginApi {
    * });
    * ```
    *
+   * @deprecated because modifying an Ember-rendered DOM tree can lead to very unexpected errors. Use plugin outlet connectors instead
    **/
   decorateTopicTitle(callback) {
+    deprecated(
+      "decorateTopicTitle is deprecated because modifying an Ember-rendered DOM tree can lead to very unexpected errors. Use plugin outlet connectors instead",
+      {
+        id: "discourse.decorate-topic-title",
+        since: "3.2",
+        dropFrom: "3.3",
+      }
+    );
     addTopicTitleDecorator(callback);
   }
 
diff --git a/app/assets/javascripts/discourse/tests/acceptance/topic-test.js b/app/assets/javascripts/discourse/tests/acceptance/topic-test.js
index 02822d44e1f..04ccbd09908 100644
--- a/app/assets/javascripts/discourse/tests/acceptance/topic-test.js
+++ b/app/assets/javascripts/discourse/tests/acceptance/topic-test.js
@@ -19,6 +19,7 @@ import {
   visible,
 } from "discourse/tests/helpers/qunit-helpers";
 import selectKit from "discourse/tests/helpers/select-kit-helper";
+import { withSilencedDeprecations } from "discourse-common/lib/deprecated";
 import { cloneJSON } from "discourse-common/lib/object";
 import I18n from "discourse-i18n";
 
@@ -463,8 +464,10 @@ acceptance("Topic with title decorated", function (needs) {
   needs.user();
   needs.hooks.beforeEach(() => {
     withPluginApi("0.8.40", (api) => {
-      api.decorateTopicTitle((topic, node, topicTitleType) => {
-        node.innerText = `${node.innerText}-${topic.id}-${topicTitleType}`;
+      withSilencedDeprecations("discourse.decorate-topic-title", () => {
+        api.decorateTopicTitle((topic, node, topicTitleType) => {
+          node.innerText = `${node.innerText}-${topic.id}-${topicTitleType}`;
+        });
       });
     });
   });