diff --git a/Rakefile b/Rakefile
index 17a93d3a28d4422249fb3eb0c80823e5c509a534..9e4521689e6d63233b414481cfcf929155d4cb35 100644
--- a/Rakefile
+++ b/Rakefile
@@ -13,7 +13,7 @@ VALIDATORS_DIR = "./generators/input-validators"
 WIKI_DIR = "./generators/wiki"
 
 # Get the list of sites as the list of directories in input/grid5000/sites
-G5K_SITES = (Dir::entries('input/grid5000/sites') - ['.', '..']).sort
+G5K_SITES = RefRepo::Utils::get_sites
 
 namespace :puppet do
 
diff --git a/lib/refrepo/gen/wiki/mw_utils.rb b/lib/refrepo/gen/wiki/mw_utils.rb
index 814e7fe554a6543763db7ac1e0dd8cfb12b82c19..0f158e084d4594e474b284bf3f5ddbd87801ad91 100644
--- a/lib/refrepo/gen/wiki/mw_utils.rb
+++ b/lib/refrepo/gen/wiki/mw_utils.rb
@@ -114,7 +114,7 @@ module G5K
     return Marshal.load(Marshal.dump(@@global_hash))
   end
 
-  SITES = get_global_hash['sites'].keys.sort
+  SITES = RefRepo::Utils::get_sites
 end
 
 #Defines MediaWiki helpers
diff --git a/lib/refrepo/utils.rb b/lib/refrepo/utils.rb
index 9924331b3653a130cdc0660fee245725df8ad3aa..b1812cd5cff981b4a0ec18d67d16af2c006860ce 100644
--- a/lib/refrepo/utils.rb
+++ b/lib/refrepo/utils.rb
@@ -17,6 +17,10 @@ module RefRepo::Utils
     d = open("#{conf['uri']}/#{conf['version']}/#{path}", o).read
     return JSON::parse(d)
   end
+
+  def self.get_sites
+    return (Dir::entries('input/grid5000/sites') - ['.', '..']).sort
+  end
 end
 
 # Various monkey patches
diff --git a/lib/refrepo/valid/oar-properties.rb b/lib/refrepo/valid/oar-properties.rb
index 9ec6e4b98cc6925ee7965b31e4c6c64e7b6ae6fd..bfa219641b2b21098d97152faa34bc7804207a05 100755
--- a/lib/refrepo/valid/oar-properties.rb
+++ b/lib/refrepo/valid/oar-properties.rb
@@ -22,13 +22,6 @@ IGNORED_PROPERTIES=%w{chassis chunks thread}
 G5K_PROPERTIES=%w{api_timestamp available_upto besteffort chunks cluster cluster_priority comment core cpu cpuarch cpucore cpufreq cpuset cputype deploy desktop_computing disk disk_reservation_count diskpath disktype drain eth_count eth_rate expiry_date finaud_decision gpu gpu_count grub host ib ib_count ib_rate id ip last_available_upto last_job_date links maintenance max_walltime memcore memcpu memnode mic myri myri_count myri_rate network_address next_finaud_decision next_state nodemodel production rconsole scheduler_priority slash_16 slash_17 slash_18 slash_19 slash_20 slash_21 slash_22 state state_num subnet_address subnet_prefix suspended_jobs switch type virtual vlan wattmeter opa opa_count opa_rate}.sort - IGNORED_PROPERTIES
 
 
-class Hash
-  def slice(*extract)
-    h2 = self.select{|key, value| extract.include?(key) }
-    h2
-  end
-end
-
 module RefRepo::Valid::OarProperties
   def self.check(options)
     ret = true