diff --git a/lib/chunks/engines.rb b/lib/chunks/engines.rb
index d7324013..a19b0978 100644
--- a/lib/chunks/engines.rb
+++ b/lib/chunks/engines.rb
@@ -85,7 +85,7 @@ module Engines
                             :html_math_output_mathml => false,
                             :html_math_output_png => true,
                             :html_png_engine => 'blahtex',
-                            :html_png_dir => @content.web.files_path + '/pngs',
+                            :html_png_dir => @content.web.files_path.join('pngs').to_s,
                             :html_png_url => '../files/pngs/',
                             :content_only => true,
                             :author => @content.options[:engine_opts][:author],
@@ -99,7 +99,7 @@ module Engines
               :html_math_output_mathml => false,
               :html_math_output_png => true,
               :html_png_engine => 'blahtex',
-              :html_png_dir => @content.web.files_path + '/pngs',
+              :html_png_dir => @content.web.files_path.join('pngs').to_s,
               :html_png_url => '../files/pngs/'}).to_html
         html.gsub(/\A<div class="maruku_wrapper_div">\n?(.*?)\n?<\/div>\Z/m, '\1')
       end
diff --git a/lib/tasks/upgrade_instiki.rake b/lib/tasks/upgrade_instiki.rake
index be075a5e..ef242c42 100644
--- a/lib/tasks/upgrade_instiki.rake
+++ b/lib/tasks/upgrade_instiki.rake
@@ -1,15 +1,16 @@
-require 'active_record'
-
 task :upgrade_instiki => :environment do
-  ActiveRecord::Base.establish_connection(:production)
-  webs = ActiveRecord::Base.connection.execute( "select * from webs" )
-  webs.each do |row|
-   if File.exists?('public/' + row[4])
-      if File.exists?('webs/' + row[4])
-        print "Warning! The directory webs/#{row[4]} already exists. Skipping.\n" 
+  RAILS_ENV = 'production' unless ENV['RAILS_ENV']
+  puts "Upgrading Instiki in #{RAILS_ENV} environment."
+
+  Web.all.each do |web|
+    public_path = Rails.root.join("public", web.address)
+    if public_path.exist?
+      webs_path = Rails.root.join("webs", web.address)
+      if webs_path.exist?
+        puts "Warning! The directory #{webs_path} already exists. Skipping."
       else
-        File.rename('public/' + row[4], 'webs/' + row[4])
-        print "Moved: #{row[4]}\n"
+        public_path.rename(webs_path)
+        puts "Moved #{public_path} to #{webs_path}"
       end
     end
   end