diff --git a/app/models/list.rb b/app/models/list.rb
index d87c3cb..4867eb0 100644
--- a/app/models/list.rb
+++ b/app/models/list.rb
@@ -13,11 +13,15 @@ def initialize(name, id)
     List.new('ruby-talk', 4),
   ]
 
-  def self.find_by_name(name)
-    LISTS.find { |list| list.name == name }
-  end
+  class << self
+    def find_by_name(name)
+      List::LISTS.find { |list| list.name == name }
+    end
+
+    def find_by_id(id)
+      List::LISTS.find { |list| list.id == id }
+    end
 
-  def self.find_by_id(id)
-    LISTS.find { |list| list.id == id }
+    alias find find_by_id
   end
 end
diff --git a/app/models/message.rb b/app/models/message.rb
index e08aa58..2896db4 100644
--- a/app/models/message.rb
+++ b/app/models/message.rb
@@ -127,7 +127,7 @@ def from_string(str)
   end
 
   def list
-    @list ||= List.find_by_id(list_id)
+    @list ||= List.find(list_id)
   end
 
   def count_recursively(count = 0)
@@ -135,7 +135,7 @@ def count_recursively(count = 0)
   end
 
   def reload_from_s3(s3_client = Aws::S3::Client.new(region: BLADE_BUCKET_REGION))
-    m = Message.from_s3(List.find_by_id(self.list_id).name, self.list_seq, s3_client)
+    m = Message.from_s3(List.find(self.list_id).name, self.list_seq, s3_client)
 
     self.body = m.body
     self.subject = m.subject
diff --git a/app/views/messages/search.html.erb b/app/views/messages/search.html.erb
index 45c2825..9ab4143 100644
--- a/app/views/messages/search.html.erb
+++ b/app/views/messages/search.html.erb
@@ -27,7 +27,7 @@
 
 <% @messages.each do |message| %>
   <div class="search-result">
-    <% list_name = List.find_by_id(message.list_id).name %>
+    <% list_name = List.find(message.list_id).name %>
     <h2 class="subject">
       <span class="prefix"><%= list_name %>:<%= message.list_seq %></span>
       <%= link_to without_list_prefix(message.subject), "/#{list_name}/#{message.list_seq}" %>