diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index e6f4959..048b410 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -77,4 +77,14 @@ class ApplicationController < ActionController::Base
     end
   end
 
+  def profile_path(user)
+    if user.username
+      public_profile_path(username: user.username)
+    else
+      unnamed_user_path(user)
+    end
+  end
+
+  helper_method :profile_path
+
 end
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 174dbbd..80bf34d 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -9,7 +9,12 @@ class UsersController < ApplicationController
   end
 
   def show
-    user = User.for_username!(params[:username])
+    if params[:username]
+      user = User.for_username!(params[:username])
+    else
+      user = User.find(params[:id])
+    end
+
     render locals: { page: UserPagePresenter.build(user, current_user, params[:page]) }
   end
 
diff --git a/app/decorators/user_decorator.rb b/app/decorators/user_decorator.rb
index 4dc6c4b..787acee 100644
--- a/app/decorators/user_decorator.rb
+++ b/app/decorators/user_decorator.rb
@@ -2,7 +2,7 @@ class UserDecorator < ApplicationDecorator
   include AvatarHelper
 
   def link
-    wrap_with_link(username || temporary_username || 'anonymous')
+    wrap_with_link(username || temporary_username || "user:#{id}")
   end
 
   def img_link
@@ -28,8 +28,9 @@ class UserDecorator < ApplicationDecorator
   private
 
   def wrap_with_link(html)
-    if username
-      h.link_to html, h.profile_path(model), title: username
+    if id
+      title = username || temporary_username || 'anonymous user'
+      h.link_to html, h.profile_path(model), title: title
     else
       html
     end
diff --git a/app/models/user.rb b/app/models/user.rb
index 05cfd37..6abb259 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -81,10 +81,6 @@ class User < ActiveRecord::Base
     theme_name.presence && Theme.for_name(theme_name)
   end
 
-  def to_param
-    username
-  end
-
   def assign_api_token(token)
     api_token = ApiToken.for_token(token)
 
diff --git a/config/routes.rb b/config/routes.rb
index 62a141e..d74118f 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -12,7 +12,8 @@ Rails.application.routes.draw do
     end
   end
 
-  get "/~:username" => "users#show", :as => :profile
+  get "/u/:id" => "users#show", as: :unnamed_user
+  get "/~:username" => "users#show", as: :public_profile
 
   namespace :api do
     resources :asciicasts