diff --git a/app/assets/javascripts/select-kit/components/topic-notifications-options.js.es6 b/app/assets/javascripts/select-kit/components/topic-notifications-options.js.es6
index 4feb3b003f1..dc48e82f09b 100644
--- a/app/assets/javascripts/select-kit/components/topic-notifications-options.js.es6
+++ b/app/assets/javascripts/select-kit/components/topic-notifications-options.js.es6
@@ -1,5 +1,5 @@
 import NotificationOptionsComponent from "select-kit/components/notifications-button";
-import { on } from "ember-addons/ember-computed-decorators";
+import { default as computed, on } from "ember-addons/ember-computed-decorators";
 import { topicLevels } from "discourse/lib/notification-levels";
 
 export default NotificationOptionsComponent.extend({
@@ -9,6 +9,11 @@ export default NotificationOptionsComponent.extend({
   i18nPrefix: "topic.notifications",
   allowInitialValueMutation: false,
 
+  @computed("topic.archetype")
+  i18nPostfix(archetype) {
+    return archetype === "private_message" ? "_pm" : "";
+  },
+
   @on("didInsertElement")
   _bindGlobalLevelChanged() {
     this.appEvents.on("topic-notifications-button:changed", (msg) => {