diff --git a/Gemfile b/Gemfile
index e3a5825..df6bd4a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -63,6 +63,7 @@ gem 'redis-rails'
 gem 'rubyzip'
 gem 'rugged'
 gem 'sucker_punch'
+gem 'symbol-fstring', require: 'fstring/all'
 gem 'terminal-table'
 gem 'validates_hostname'
 gem 'webpacker'
diff --git a/Gemfile.lock b/Gemfile.lock
index e2ad391..09be6cc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -505,6 +505,7 @@ GEM
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
+    symbol-fstring (1.0.0)
     sysexits (1.2.0)
     temple (0.8.2)
     terminal-table (1.8.0)
@@ -613,6 +614,7 @@ DEPENDENCIES
   sutty-donaciones-jekyll-theme
   sutty-jekyll-theme
   sutty-minima
+  symbol-fstring
   terminal-table
   timecop
   turbolinks (~> 5)
diff --git a/app/models/access_log.rb b/app/models/access_log.rb
new file mode 100644
index 0000000..85cd4c3
--- /dev/null
+++ b/app/models/access_log.rb
@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+class AccessLog < ApplicationRecord
+end
diff --git a/app/models/metadata_has_and_belongs_to_many.rb b/app/models/metadata_has_and_belongs_to_many.rb
index 92b4581..4cc0c36 100644
--- a/app/models/metadata_has_and_belongs_to_many.rb
+++ b/app/models/metadata_has_and_belongs_to_many.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Establece una relación de muchos a muchos artículos.  Cada campo es un
 # Array de UUID que se mantienen sincronizados.
 #
diff --git a/app/models/metadata_tel.rb b/app/models/metadata_tel.rb
index 8e3ae59..2df332e 100644
--- a/app/models/metadata_tel.rb
+++ b/app/models/metadata_tel.rb
@@ -1 +1,3 @@
+# frozen_string_literal: true
+
 class MetadataTel < MetadataNumber; end