diff --git a/app/assets/javascripts/discourse/components/composer-messages.js.es6 b/app/assets/javascripts/discourse/components/composer-messages.js.es6
index 4fd967ade22..8830fd19394 100644
--- a/app/assets/javascripts/discourse/components/composer-messages.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-messages.js.es6
@@ -119,18 +119,15 @@ export default Ember.Component.extend({
     // We don't care about similar topics unless creating a topic
     if (!composer.get('creatingTopic')) { return; }
 
-    const origBody = composer.get('reply') || '';
+    // TODO pass the 200 in from somewhere
+    const raw = (composer.get('reply') || '').substr(0, 200);
     const title = composer.get('title') || '';
 
-    // Ensure the fields are of the minimum length
-    if (origBody.length < Discourse.SiteSettings.min_body_similar_length) { return; }
-    if (title.length < Discourse.SiteSettings.min_title_similar_length) { return; }
-
-    // TODO pass the 200 in from somewhere
-    const body = origBody.substr(0, 200);
+    // Ensure we have at least a title
+    if (title.length < this.siteSettings.min_title_similar_length) { return; }
 
     // Don't search over and over
-    const concat = title + body;
+    const concat = title + raw;
     if (concat === this._lastSimilaritySearch) { return; }
     this._lastSimilaritySearch = concat;
 
@@ -143,14 +140,15 @@ export default Ember.Component.extend({
 
     this._similarTopicsMessage = message;
 
-    composer.store.find('similar-topic', {title, raw: body}).then(newTopics => {
+    composer.store.find('similar-topic', { title, raw }).then(topics => {
       similarTopics.clear();
-      similarTopics.pushObjects(newTopics.get('content'));
+      similarTopics.pushObjects(topics.get('content'));
 
       if (similarTopics.get('length') > 0) {
         message.set('similarTopics', similarTopics);
         this.send('popup', message);
       } else if (message) {
+        debugger
         this.send('hideMessage', message);
       }
     });
diff --git a/app/controllers/similar_topics_controller.rb b/app/controllers/similar_topics_controller.rb
index 8070697e57c..e6249cb4d4f 100644
--- a/app/controllers/similar_topics_controller.rb
+++ b/app/controllers/similar_topics_controller.rb
@@ -16,25 +16,16 @@ class SimilarTopicsController < ApplicationController
   end
 
   def index
-    params.require(:title)
-    params.require(:raw)
-    title, raw = params[:title], params[:raw]
-    invalid_length = [:title, :raw].any? { |key| check_invalid_length(key, params[key]) }
+    title = params.require(:title)
+    raw = params[:raw]
 
-    # Only suggest similar topics if the site has a minimum amount of topics present
-    # and params are long enough.
-    return render json: [] if invalid_length || !Topic.count_exceeds_minimum?
+    if title.length < SiteSetting.min_title_similar_length || !Topic.count_exceeds_minimum?
+      return render json: []
+    end
 
     topics = Topic.similar_to(title, raw, current_user).to_a
     topics.map! { |t| SimilarTopic.new(t) }
     render_serialized(topics, SimilarTopicSerializer, root: :similar_topics, rest_serializer: true)
   end
 
-  protected
-
-    def check_invalid_length(key, attr)
-      str = (key == :raw) ? "body" : key.to_s
-      attr.length < SiteSetting.send("min_#{str}_similar_length")
-    end
-
 end
diff --git a/app/models/topic.rb b/app/models/topic.rb
index 52aa1255e5f..12ee2ea2ae7 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -436,42 +436,46 @@ class Topic < ActiveRecord::Base
     archetype == Archetype.private_message
   end
 
-  MAX_SIMILAR_BODY_LENGTH = 200
-  # Search for similar topics
-  def self.similar_to(title, raw, user = nil)
-    return [] unless title.present?
-    return [] unless raw.present?
+  MAX_SIMILAR_BODY_LENGTH ||= 200
 
-    filter_words = Search.prepare_data(title + " " + raw[0...MAX_SIMILAR_BODY_LENGTH]);
+  def self.similar_to(title, raw, user = nil)
+    return [] if title.blank?
+    raw = raw.presence || ""
+
+    search_data = "#{title} #{raw[0...MAX_SIMILAR_BODY_LENGTH]}".strip
+    filter_words = Search.prepare_data(search_data)
     ts_query = Search.ts_query(filter_words, nil, "|")
 
-    # Exclude category definitions from similar topic suggestions
-
-    candidates = Topic.visible
-      .secured(Guardian.new(user))
+    candidates = Topic
+      .visible
       .listable_topics
-      .joins('JOIN topic_search_data s ON topics.id = s.topic_id')
+      .secured(Guardian.new(user))
+      .joins("JOIN topic_search_data s ON topics.id = s.topic_id")
+      .joins("LEFT JOIN categories c ON topics.id = c.topic_id")
       .where("search_data @@ #{ts_query}")
+      .where("c.topic_id IS NULL")
       .order("ts_rank(search_data, #{ts_query}) DESC")
       .limit(SiteSetting.max_similar_results * 3)
 
-    exclude_topic_ids = Category.pluck(:topic_id).compact!
-    if exclude_topic_ids.present?
-      candidates = candidates.where("topics.id NOT IN (?)", exclude_topic_ids)
-    end
-
     candidate_ids = candidates.pluck(:id)
 
-    return [] unless candidate_ids.present?
+    return [] if candidate_ids.blank?
 
-    similar = Topic.select(sanitize_sql_array(["topics.*, similarity(topics.title, :title) + similarity(topics.title, :raw) AS similarity, p.cooked as blurb", title: title, raw: raw]))
+    similars = Topic
       .joins("JOIN posts AS p ON p.topic_id = topics.id AND p.post_number = 1")
-      .limit(SiteSetting.max_similar_results)
       .where("topics.id IN (?)", candidate_ids)
-      .where("similarity(topics.title, :title) + similarity(topics.title, :raw) > 0.2", raw: raw, title: title)
-      .order('similarity desc')
+      .order("similarity DESC")
+      .limit(SiteSetting.max_similar_results)
 
-    similar
+    if raw.present?
+      similars
+        .select(sanitize_sql_array(["topics.*, similarity(topics.title, :title) + similarity(p.raw, :raw) AS similarity, p.cooked AS blurb", title: title, raw: raw]))
+        .where("similarity(topics.title, :title) + similarity(p.raw, :raw) > 0.2", title: title, raw: raw)
+    else
+      similars
+        .select(sanitize_sql_array(["topics.*, similarity(topics.title, :title) AS similarity, p.cooked AS blurb", title: title]))
+        .where("similarity(topics.title, :title) > 0.2", title: title)
+    end
   end
 
   def update_status(status, enabled, user, opts = {})
@@ -481,7 +485,7 @@ class Topic < ActiveRecord::Base
 
   # Atomically creates the next post number
   def self.next_post_number(topic_id, reply = false, whisper = false)
-    highest = exec_sql("select coalesce(max(post_number),0) as max from posts where topic_id = ?", topic_id).first['max'].to_i
+    highest = exec_sql("SELECT coalesce(max(post_number),0) AS max FROM posts WHERE topic_id = ?", topic_id).first['max'].to_i
 
     if whisper
 
diff --git a/config/site_settings.yml b/config/site_settings.yml
index 85ba28dd91e..52363b76122 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -499,12 +499,6 @@ posting:
     locale_default:
       zh_CN: 4
       zh_TW: 4
-  min_body_similar_length:
-    client: true
-    default: 15
-    locale_default:
-      zh_CN: 5
-      zh_TW: 5
   enable_private_messages:
     default: true
     client: true
diff --git a/lib/search.rb b/lib/search.rb
index dd70d9b5a2b..4baf419fd3b 100644
--- a/lib/search.rb
+++ b/lib/search.rb
@@ -50,9 +50,7 @@ class Search
     data = search_data.squish
     # TODO cppjieba_rb is designed for chinese, we need something else for Korean / Japanese
     if ['zh_TW', 'zh_CN', 'ja', 'ko'].include?(SiteSetting.default_locale) || SiteSetting.search_tokenize_chinese_japanese_korean
-      unless defined? CppjiebaRb
-        require 'cppjieba_rb'
-      end
+      require 'cppjieba_rb' unless defined? CppjiebaRb
       mode = (purpose == :query ? :query : :mix)
       data = CppjiebaRb.segment(search_data, mode: mode)
       data = CppjiebaRb.filter_stop_word(data).join(' ')
diff --git a/spec/controllers/similar_topics_controller_spec.rb b/spec/controllers/similar_topics_controller_spec.rb
index 605bed1d6a6..e14432ecced 100644
--- a/spec/controllers/similar_topics_controller_spec.rb
+++ b/spec/controllers/similar_topics_controller_spec.rb
@@ -10,10 +10,6 @@ describe SimilarTopicsController do
       expect { xhr :get, :index, raw: raw }.to raise_error(ActionController::ParameterMissing)
     end
 
-    it "requires a raw body" do
-      expect { xhr :get, :index, title: title }.to raise_error(ActionController::ParameterMissing)
-    end
-
     it "returns no results if the title length is below the minimum" do
       Topic.expects(:similar_to).never
       SiteSetting.min_title_similar_length = 100
@@ -22,14 +18,6 @@ describe SimilarTopicsController do
       expect(json["similar_topics"].size).to eq(0)
     end
 
-    it "returns no results if the body length is below the minimum" do
-      Topic.expects(:similar_to).never
-      SiteSetting.min_body_similar_length = 100
-      xhr :get, :index, title: title, raw: raw
-      json = ::JSON.parse(response.body)
-      expect(json["similar_topics"].size).to eq(0)
-    end
-
     describe "minimum_topics_similar" do
 
       before do
diff --git a/test/javascripts/helpers/site-settings.js b/test/javascripts/helpers/site-settings.js
index e44e4434e14..7f48f999477 100644
--- a/test/javascripts/helpers/site-settings.js
+++ b/test/javascripts/helpers/site-settings.js
@@ -48,7 +48,6 @@ Discourse.SiteSettingsOriginal = {
   "min_private_message_title_length":2,
   "allow_uncategorized_topics":true,
   "min_title_similar_length":10,
-  "min_body_similar_length":15,
   "edit_history_visible_to_public":true,
   "delete_removed_posts_after":24,
   "traditional_markdown_linebreaks":false,