diff --git a/app/assets/javascripts/discourse/controllers/composer.js.es6 b/app/assets/javascripts/discourse/controllers/composer.js.es6
index cf839d8e8ac..ad34970e5bc 100644
--- a/app/assets/javascripts/discourse/controllers/composer.js.es6
+++ b/app/assets/javascripts/discourse/controllers/composer.js.es6
@@ -187,8 +187,15 @@ export default Controller.extend({
     );
   },
 
-  disableCategoryChooser: Ember.computed.not("model.topic.details.can_edit"),
-  disableTagsChooser: Ember.computed.not("model.topic.canEditTags"),
+  @computed("model.editingPost", "model.topic.details.can_edit")
+  disableCategoryChooser(editingPost, canEditTopic) {
+    return editingPost && !canEditTopic;
+  },
+
+  @computed("model.editingPost", "model.topic.canEditTags")
+  disableTagsChooser(editingPost, canEditTags) {
+    return editingPost && !canEditTags;
+  },
 
   isStaffUser: Ember.computed.reads("currentUser.staff"),
 
diff --git a/app/assets/javascripts/discourse/models/composer.js.es6 b/app/assets/javascripts/discourse/models/composer.js.es6
index 34b44985df0..686d98c5fbf 100644
--- a/app/assets/javascripts/discourse/models/composer.js.es6
+++ b/app/assets/javascripts/discourse/models/composer.js.es6
@@ -141,7 +141,11 @@ const Composer = RestModel.extend({
   creatingPrivateMessage: Ember.computed.equal("action", PRIVATE_MESSAGE),
   notCreatingPrivateMessage: Ember.computed.not("creatingPrivateMessage"),
   notPrivateMessage: Ember.computed.not("privateMessage"),
-  disableTitleInput: Ember.computed.not("topic.details.can_edit"),
+
+  @computed("editingPost", "topic.details.can_edit")
+  disableTitleInput(editingPost, canEditTopic) {
+    return editingPost && !canEditTopic;
+  },
 
   @computed("privateMessage", "archetype.hasOptions")
   showCategoryChooser(isPrivateMessage, hasOptions) {