diff --git a/app/logical/user_name_validator.rb b/app/logical/user_name_validator.rb
new file mode 100644
index 000000000..c86c693db
--- /dev/null
+++ b/app/logical/user_name_validator.rb
@@ -0,0 +1,10 @@
+class UserNameValidator < ActiveModel::EachValidator
+  def validate_each(rec, attr, value)
+    name = User.normalize_name(value)
+
+    rec.errors[attr] << "already exists" if User.find_by_name(name).present?
+    rec.errors[attr] << "must be 2 to 100 characters long" if !name.length.between?(2, 100)
+    rec.errors[attr] << "cannot have whitespace or colons" if name =~ /[[:space:]]|:/
+    rec.errors[attr] << "cannot begin or end with an underscore" if name =~ /\A_|_\z/
+  end
+end
diff --git a/app/models/user.rb b/app/models/user.rb
index 73a29581d..6c0ac9129 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -54,10 +54,8 @@ class User < ActiveRecord::Base
   attr_accessor :password, :old_password
   attr_accessible :dmail_filter_attributes, :enable_privacy_mode, :enable_post_navigation, :new_post_navigation_layout, :password, :old_password, :password_confirmation, :password_hash, :email, :last_logged_in_at, :last_forum_read_at, :has_mail, :receive_email_notifications, :comment_threshold, :always_resize_images, :favorite_tags, :blacklisted_tags, :name, :ip_addr, :time_zone, :default_image_size, :enable_sequential_post_navigation, :per_page, :hide_deleted_posts, :style_usernames, :enable_auto_complete, :custom_style, :show_deleted_children, :disable_categorized_saved_searches, :disable_tagged_filenames, :enable_recent_searches, :as => [:moderator, :janitor, :gold, :platinum, :member, :anonymous, :default, :builder, :admin]
   attr_accessible :level, :as => :admin
-  validates_length_of :name, :within => 2..100, :on => :create
-  validates_format_of :name, :with => /\A[^\s:]+\Z/, :on => :create, :message => "cannot have whitespace or colons"
-  validates_format_of :name, :with => /\A[^_].*[^_]\Z/, :on => :create, :message => "cannot begin or end with an underscore"
-  validates_uniqueness_of :name, :case_sensitive => false
+
+  validates :name, user_name: true, on: :create
   validates_uniqueness_of :email, :case_sensitive => false, :if => lambda {|rec| rec.email.present? && rec.email_changed? }
   validates_length_of :password, :minimum => 5, :if => lambda {|rec| rec.new_record? || rec.password.present?}
   validates_inclusion_of :default_image_size, :in => %w(large original)
@@ -153,6 +151,10 @@ class User < ActiveRecord::Base
       def id_to_pretty_name(user_id)
         id_to_name(user_id).gsub(/([^_])_+(?=[^_])/, "\\1 \\2")
       end
+
+      def normalize_name(name)
+        name.to_s.mb_chars.downcase.strip.tr(" ", "_").to_s
+      end
     end
 
     def pretty_name
diff --git a/app/models/user_name_change_request.rb b/app/models/user_name_change_request.rb
index eaf8cd372..b7de494f9 100644
--- a/app/models/user_name_change_request.rb
+++ b/app/models/user_name_change_request.rb
@@ -3,11 +3,8 @@ class UserNameChangeRequest < ActiveRecord::Base
   validates_inclusion_of :status, :in => %w(pending approved rejected)
   belongs_to :user
   belongs_to :approver, :class_name => "User"
-  validate :uniqueness_of_desired_name
   validate :not_limited, :on => :create
-  validates_length_of :desired_name, :within => 2..100, :on => :create
-  validates_format_of :desired_name, :with => /\A[^\s:]+\Z/, :on => :create, :message => "cannot have whitespace or colons"
-  before_validation :normalize_name
+  validates :desired_name, user_name: true
   attr_accessible :status, :user_id, :original_name, :desired_name, :change_reason, :rejection_reason, :approver_id
   
   def self.pending
@@ -40,8 +37,8 @@ class UserNameChangeRequest < ActiveRecord::Base
     status == "pending"
   end
   
-  def normalize_name
-    self.desired_name = desired_name.strip.gsub(/ /, "_")
+  def desired_name=(name)
+    super(User.normalize_name(name))
   end
   
   def feedback
@@ -71,15 +68,6 @@ class UserNameChangeRequest < ActiveRecord::Base
       return true
     end
   end
-  
-  def uniqueness_of_desired_name
-    if User.find_by_name(desired_name)
-      errors.add(:desired_name, "already exists")
-      return false
-    else
-      return true
-    end
-  end
 
   def hidden_attributes
     if CurrentUser.is_admin? || user == CurrentUser.user
diff --git a/test/unit/user_test.rb b/test/unit/user_test.rb
index ffb505616..523ff75e8 100644
--- a/test/unit/user_test.rb
+++ b/test/unit/user_test.rb
@@ -187,6 +187,13 @@ class UserTest < ActiveSupport::TestCase
         assert_equal(Danbooru.config.default_guest_name, User.id_to_name(-1))
       end
 
+      should "not contain whitespace" do
+        # U+2007: https://en.wikipedia.org/wiki/Figure_space
+        user = FactoryGirl.build(:user, :name => "foo\u2007bar")
+        user.save
+        assert_equal(["Name cannot have whitespace or colons"], user.errors.full_messages)
+      end
+
       should "not contain a colon" do
         user = FactoryGirl.build(:user, :name => "a:b")
         user.save