diff --git a/lib/tasks/2018_04_11_admin_or_gestionnaire_users.rake b/lib/tasks/2018_04_11_admin_or_gestionnaire_users.rake
new file mode 100644
index 000000000..ce37c088b
--- /dev/null
+++ b/lib/tasks/2018_04_11_admin_or_gestionnaire_users.rake
@@ -0,0 +1,31 @@
+namespace :'2018_04_11_admin_or_gestionnaire_users' do
+  task create_missing: :environment do
+    create_missing_users(Administrateur)
+    create_missing_users(Gestionnaire)
+  end
+
+  def create_missing_users(klass)
+    klasses = klass.name.downcase.pluralize
+    accounts = klass.joins("LEFT JOIN users on users.email = #{klasses}.email").where('users.id is null')
+    processed_count = 0
+
+    accounts.find_each(batch_size: 100) do |account|
+      # To pass validation, we need to set dummy password even though
+      # we override encrypted_password afterwards
+
+      user = User.create({
+        email: account.email,
+        password: SecureRandom.hex(5),
+        encrypted_password: account.encrypted_password
+      })
+
+      if user.persisted?
+        processed_count += 1
+      else
+        print "Failed to create user for #{account.email}\n"
+      end
+    end
+
+    print "Created users for #{processed_count} #{klasses}\n"
+  end
+end