diff --git a/app/models/setting.rb b/app/models/setting.rb
index 16e51fd53..92e327954 100644
--- a/app/models/setting.rb
+++ b/app/models/setting.rb
@@ -82,6 +82,8 @@ class Setting < ActiveRecord::Base
                   Big5-HKSCS
                   TIS-620)
 
+  MINIMUM_API_LIMIT = 100
+
   cattr_accessor :available_settings
   self.available_settings ||= {}
 
@@ -191,6 +193,11 @@ class Setting < ActiveRecord::Base
         messages << [:mail_from, l('activerecord.errors.messages.invalid')]
       end
     end
+    if settings.key?(:api_limit)
+      if settings[:api_limit].to_i < MINIMUM_API_LIMIT
+        messages << [:api_limit, l('activerecord.errors.messages.greater_than_or_equal_to', MINIMUM_API_LIMIT)]
+      end
+    end
     messages
   end
 
diff --git a/test/unit/setting_test.rb b/test/unit/setting_test.rb
index 45f97f8da..6a35d10c7 100644
--- a/test/unit/setting_test.rb
+++ b/test/unit/setting_test.rb
@@ -145,4 +145,14 @@ class SettingTest < ActiveSupport::TestCase
       end
     end
   end
+
+  def test_api_limit_format_should_be_validated
+    with_locale 'en' do
+      errors = Setting.set_all_from_params({api_limit: (Setting::MINIMUM_API_LIMIT - 1).to_s})
+      assert_includes errors, [:api_limit, "must be greater than or equal to #{Setting::MINIMUM_API_LIMIT}"]
+
+      errors = Setting.set_all_from_params({api_limit: Setting::MINIMUM_API_LIMIT.to_s})
+      assert_nil errors
+    end
+  end
 end