diff --git a/config/initializers/noosfero_urls.rb b/config/initializers/noosfero_urls.rb
index 60b2a14..c4e37ee 100644
--- a/config/initializers/noosfero_urls.rb
+++ b/config/initializers/noosfero_urls.rb
@@ -1,5 +1,13 @@
 if Rails.env == 'development'
   ActionController::Base.send(:prepend_before_filter) do |controller|
-    Noosfero.instance_variable_set('@development_url_options', { :port => controller.request.port })
+    # XXX note that this is not thread-safe! Accessing a Noosfero instance in
+    # development mode under different ports concurrently _will_ lead to weird
+    # things happening.
+    if [80,443].include?(controller.request.port)
+      url_options = {}
+    else
+      url_options = { :port => controller.request.port }
+    end
+    Noosfero.instance_variable_set('@development_url_options', url_options)
   end
 end
--
libgit2 0.21.2