diff --git a/app/models/post_analyzer.rb b/app/models/post_analyzer.rb
index 4e2bf369e81..70f1bf01233 100644
--- a/app/models/post_analyzer.rb
+++ b/app/models/post_analyzer.rb
@@ -11,7 +11,7 @@ class PostAnalyzer
   def cook(*args)
     cooked = PrettyText.cook(*args)
 
-    result = Oneboxer.apply(cooked) do |url, _|
+    result = Oneboxer.apply(cooked, topic_id: @topic_id) do |url, _|
       Oneboxer.invalidate(url) if args.last[:invalidate_oneboxes]
       Oneboxer.cached_onebox url
     end
diff --git a/lib/cooked_post_processor.rb b/lib/cooked_post_processor.rb
index a74e4fa7414..9c606a23dd4 100644
--- a/lib/cooked_post_processor.rb
+++ b/lib/cooked_post_processor.rb
@@ -245,19 +245,7 @@ class CookedPostProcessor
     }
 
     # apply oneboxes
-    Oneboxer.apply(@doc) { |url|
-
-      # hack urls to create proper expansions
-      if url =~ Regexp.new("^#{Discourse.base_url.gsub(".","\\.")}.*$", true)
-        uri = URI.parse(url) rescue nil
-        if uri && uri.path
-          route = Rails.application.routes.recognize_path(uri.path) rescue nil
-          if route && route[:controller] == 'topics'
-            url += (url =~ /\?/ ? "&" : "?") + "&source_topic_id=#{@post.topic_id}"
-          end
-        end
-      end
-
+    Oneboxer.apply(@doc, topic_id: @post.topic_id) { |url|
       Oneboxer.onebox(url, args)
     }
 
diff --git a/lib/oneboxer.rb b/lib/oneboxer.rb
index 50aa8bc7b06..5557b8e750e 100644
--- a/lib/oneboxer.rb
+++ b/lib/oneboxer.rb
@@ -76,12 +76,30 @@ module Oneboxer
     doc
   end
 
-  def self.apply(string_or_doc)
+  def self.append_source_topic_id(url, topic_id)
+    # hack urls to create proper expansions
+    if url =~ Regexp.new("^#{Discourse.base_url.gsub(".","\\.")}.*$", true)
+      uri = URI.parse(url) rescue nil
+      if uri && uri.path
+        route = Rails.application.routes.recognize_path(uri.path) rescue nil
+        if route && route[:controller] == 'topics'
+          url += (url =~ /\?/ ? "&" : "?") + "source_topic_id=#{topic_id}"
+        end
+      end
+    end
+    url
+  end
+
+  def self.apply(string_or_doc, args=nil)
     doc = string_or_doc
     doc = Nokogiri::HTML::fragment(doc) if doc.is_a?(String)
     changed = false
 
     Oneboxer.each_onebox_link(doc) do |url, element|
+
+      if args && args[:topic_id]
+        url = append_source_topic_id(url, args[:topic_id])
+      end
       onebox, _preview = yield(url,element)
       if onebox
         parsed_onebox = Nokogiri::HTML::fragment(onebox)