diff --git a/lib/tasks/support.rake b/lib/tasks/support.rake
index e4832dd67..d889ecb17 100644
--- a/lib/tasks/support.rake
+++ b/lib/tasks/support.rake
@@ -48,4 +48,26 @@ namespace :support do
     user.dossiers.each(&:delete_and_keep_track)
     user.destroy
   end
+
+  desc <<~EOD
+    Change the SIRET for a given dossier (specified by DOSSIER_ID)
+  EOD
+  task update_dossier_siret: :environment do
+    siret_number = ENV['SIRET']
+    dossier_id = ENV['DOSSIER_ID']
+
+    if siret_number.nil?
+      fail "Must specify a SIRET"
+    end
+
+    siret_number = siret_number.dup # Unfreeze the string
+    siret = Siret.new(siret: siret_number)
+    if siret.invalid?
+      fail siret.errors.full_messages.to_sentence
+    end
+
+    dossier = Dossier.find(dossier_id)
+
+    EtablissementUpdateJob.perform_now(dossier, siret_number)
+  end
 end