diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index ef7cf401..44ecd154 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -103,6 +103,8 @@ def unlock_achievements
   end
 
   def user_params
-    params.require(:user).permit(:accepted_coc, :aoc_id, :city_id, :entered_hardcore, :event_awareness, :favourite_language, :username)
+    params
+      .require(:user)
+      .permit(:accepted_coc, :aoc_id, :city_id, :entered_hardcore, :event_awareness, :favourite_language, :username)
   end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 929864eb..734d13bd 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -34,6 +34,8 @@ class User < ApplicationRecord
   validate :referrer_must_exist,               on: :update, if: :referrer_id_changed?
   validate :referrer_cannot_be_self,           on: :update
 
+  before_validation :blank_language_to_nil
+
   scope :admins, -> { where(uid: ADMINS.values) }
   scope :confirmed, -> { where(accepted_coc: true, synced: true).where.not(aoc_id: nil) }
   scope :insanity, -> { where(entered_hardcore: true) }
@@ -162,6 +164,12 @@ def batch_cannot_be_changed
     errors.add(:batch, "can't be changed")
   end
 
+  def blank_language_to_nil
+    return if favourite_language.present?
+
+    self.favourite_language = nil
+  end
+
   def referrer_must_exist
     errors.add(:referrer, "must exist") unless User.exists?(referrer_id)
   end