diff --git a/app/models/metadata_template.rb b/app/models/metadata_template.rb
index d53a0459..e6c0763a 100644
--- a/app/models/metadata_template.rb
+++ b/app/models/metadata_template.rb
@@ -82,7 +82,7 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
   #
   # Ver ActionText::ContentHelper#sanitize_action_text_content
   def sanitize(string)
-    return unless string
+    return if string.nil?
     return string unless string.is_a? String
 
     sanitizer.sanitize(string,
diff --git a/test/models/metadata_boolean_test.rb b/test/models/metadata_boolean_test.rb
new file mode 100644
index 00000000..05a4dd50
--- /dev/null
+++ b/test/models/metadata_boolean_test.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class MetadataBooleanTest < ActiveSupport::TestCase
+  test 'son false por defecto' do
+    site = create :site
+    post = site.posts.build
+
+    assert_equal false, post.draft.value
+
+    site.destroy
+  end
+
+  test 'pueden ser 0' do
+    site = create :site
+    post = site.posts.build
+
+    post.draft.value = '0'
+
+    assert_equal false, post.draft.value
+
+    post.save
+
+    assert_equal false, post.draft.value
+
+    site.destroy
+  end
+
+  test 'pueden ser 1' do
+    site = create :site
+    post = site.posts.build
+
+    post.draft.value = '1'
+
+    assert_equal true, post.draft.value
+
+    post.save
+
+    assert_equal true, post.draft.value
+
+    site.destroy
+  end
+
+  test 'pueden ser false' do
+    site = create :site
+    post = site.posts.build
+
+    post.draft.value = false
+
+    assert_equal false, post.draft.value
+
+    post.save
+
+    assert_equal false, post.draft.value
+
+    site.destroy
+  end
+
+  test 'pueden ser true' do
+    site = create :site
+    post = site.posts.build
+
+    post.draft.value = true
+
+    assert_equal true, post.draft.value
+
+    post.save
+
+    assert_equal true, post.draft.value
+
+    site.destroy
+  end
+end