diff --git a/app/helpers/admin/configs_helper.rb b/app/helpers/admin/configs_helper.rb
index e2ce7a0d..056f5cff 100644
--- a/app/helpers/admin/configs_helper.rb
+++ b/app/helpers/admin/configs_helper.rb
@@ -41,6 +41,7 @@ module Admin::ConfigsHelper
   # @todo find out how to pass +checked_value+ and +unchecked_value+ to +input_field+
   def config_input_field(form, key, options = {})
     return unless @cfg.allowed_key? :key
+    options[:required] ||= false
     config_input_field_options form, key, options
     config_input_tooltip_options form, key, options
     if options[:as] == :boolean
diff --git a/config/environments/test.rb b/config/environments/test.rb
index f389ad59..f0349f7c 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -7,6 +7,9 @@ Foodsoft::Application.configure do
   # and recreated between test runs. Don't rely on the data there!
   config.cache_classes = true
 
+  # We clear the cache for each test, let's do that in memory.
+  config.cache_store = :memory_store
+
   # Do not eager load code on boot. This avoids loading your whole application
   # just for the purpose of running a single test. If you are using a tool that
   # preloads Rails for running tests, you may have to set it to true.
diff --git a/lib/foodsoft_config.rb b/lib/foodsoft_config.rb
index 6d224279..4d4c67db 100644
--- a/lib/foodsoft_config.rb
+++ b/lib/foodsoft_config.rb
@@ -8,6 +8,26 @@
 # In addition to the configuration file, values can be overridden in the database
 # using {RailsSettings::CachedSettings} as +foodcoop.<foodcoop_scope>.**+.
 #
+# Some values may not be set in the database (e.g. the database connection to
+# sharedlists, or +default_scope+), these are defined as children of the
+# +protected+ key. The default contains a sensible list, but you can modify
+# that. Here's an almost minimal example:
+#
+#     default:
+#       default_scope: f
+#       host: order.foodstuff.test      # hostname for urls in emails
+#
+#       name: Fairy Foodstuff           # the name of our foodcoop
+#       contact:
+#         # ...
+#         email: fairy@foodstuff.test   # general contact email address
+#
+#       price_markup: 6                 # foodcoop margin
+#
+#       protected:
+#         shared_lists: false           # allow database connection override
+#         use_messages: true            # foodcoops can't disable the use of messages
+#
 class FoodsoftConfig
 
   # @!attribute scope
@@ -132,10 +152,14 @@ class FoodsoftConfig
     # @return [Boolean] Whether this key may be set in the database
     def allowed_key?(key)
       # fast check for keys without nesting
-      return !self.config[:protected].keys.include?(key.to_s)
+      return !self.config[:protected][key]
       # @todo allow to check nested keys as well
     end
 
+    # @return [Hash] Full configuration.
+    def to_hash
+      Hash[keys.map {|k| [k, self[k]]} ]
+    end
 
     protected
 
@@ -185,16 +209,19 @@ class FoodsoftConfig
       ActiveRecord::Base.establish_connection(database_config)
     end
 
-    # When new options are introduced, put backward-compatible defaults here, so that
-    # configuration files that haven't been updated, still work as they did. This also
-    # makes sure that the configuration editor picks up the defaults.
-    # @see #default_foodsoft_config
+    # Completes foodcoop configuration with program defaults.
+    # @see #foodsoft_config
     def set_missing
-      config.replace(default_config.merge(config))
+      config.replace(default_config.deep_merge(config))
     end
 
+    # Returns program-default configuration.
+    #   When new options are introduced, put backward-compatible defaults here, so that
+    #   configuration files that haven't been updated, still work as they did. This also
+    #   makes sure that the configuration editor picks up the defaults.
     # @return [Hash] Program-default foodcoop configuration.
     # @see #default_config
+    # @see #set_missing
     def get_default_config
       cfg = {
         use_nick: true,
@@ -202,14 +229,14 @@ class FoodsoftConfig
         # English is the default language, and this makes it show up as default.
         default_locale: 'en',
         foodsoft_url: 'https://github.com/foodcoops/foodsoft',
-        # The following keys cannot be set by foodcoops themselves.
+        # The following keys cannot, by default, be set by foodcoops themselves.
         protected: {
-          multi_coop_install: nil,
-          default_scope: nil,
-          notification: nil,
-          shared_lists: nil,
-          protected: nil,
-          database: nil
+          multi_coop_install: true,
+          default_scope: true,
+          notification: true,
+          shared_lists: true,
+          protected: true,
+          database: true
         }
       }
       # allow engines to easily add to this
diff --git a/spec/app_config.yml b/spec/app_config.yml
index f9d0ed81..5da8aa3c 100644
--- a/spec/app_config.yml
+++ b/spec/app_config.yml
@@ -13,6 +13,9 @@ default: &defaults
   contact:
     email: fc@minimal.test
 
+  # required by configuration form (but otherwise not)
+  homepage: http://www.minimal.test/
+
   # true by default to keep compat with older installations, but test with false here
   use_nick: false
 
diff --git a/spec/integration/config_spec.rb b/spec/integration/config_spec.rb
new file mode 100644
index 00000000..d62f0894
--- /dev/null
+++ b/spec/integration/config_spec.rb
@@ -0,0 +1,45 @@
+require_relative '../spec_helper'
+
+describe 'admin/configs', type: :feature do
+  let(:name) { Faker::Lorem.words(rand(2..4)).join(' ') }
+
+  describe type: :feature, js: true do
+    let(:admin) { create :admin }
+    before { login admin }
+
+    it 'has initial value' do
+      FoodsoftConfig[:name] = name
+      visit admin_config_path
+      within('form.config') do
+        expect(find_field('config_name').value).to eq name
+      end
+    end
+
+    it 'can modify a value' do
+      visit admin_config_path
+      fill_in 'config_name', with: name
+      within('form.config') do
+        find('input[type="submit"]').click
+        expect(find_field('config_name').value).to eq name
+      end
+      expect(FoodsoftConfig[:name]).to eq name
+    end
+
+    it 'keeps config the same without changes' do
+      orig_values = get_full_config
+      visit admin_config_path
+      within('form.config') do
+        find('input[type="submit"]').click
+        expect(find_field('config_name').value).to eq FoodsoftConfig[:name]
+      end
+      expect(get_full_config).to eq orig_values
+    end
+
+    def get_full_config
+      cfg = FoodsoftConfig.to_hash.deep_dup
+      cfg.each {|k,v| v.reject! {|k,v| v.blank?} if v.is_a? Hash}
+      cfg
+    end
+
+  end
+end
diff --git a/spec/lib/foodsoft_config_spec.rb b/spec/lib/foodsoft_config_spec.rb
new file mode 100644
index 00000000..6b35a3c2
--- /dev/null
+++ b/spec/lib/foodsoft_config_spec.rb
@@ -0,0 +1,85 @@
+require_relative '../spec_helper'
+
+describe FoodsoftConfig do
+  let(:name) { Faker::Lorem.words(rand(2..4)).join(' ') }
+  let(:other_name) { Faker::Lorem.words(rand(2..4)).join(' ') }
+
+  it 'returns a default value' do
+    expect(FoodsoftConfig[:protected][:database]).to be_true
+  end
+
+  it 'returns an empty default value' do
+    expect(FoodsoftConfig[:protected][:LIUhniuyGNKUQTWfbiOQIWYexngo78hqexul]).to be_false
+  end
+
+  it 'returns a configuration value' do
+    FoodsoftConfig.config[:name] = name
+    expect(FoodsoftConfig[:name]).to eq name
+  end
+
+  it 'can set a configuration value' do
+    FoodsoftConfig[:name] = name
+    expect(FoodsoftConfig[:name]).to eq name
+  end
+
+  it 'can override a configuration value' do
+    FoodsoftConfig.config[:name] = name
+    FoodsoftConfig[:name] = other_name
+    expect(FoodsoftConfig[:name]).to eq other_name
+  end
+
+  it 'cannot set a default protected value' do
+    old = FoodsoftConfig[:database]
+    FoodsoftConfig[:database] = name
+    expect(FoodsoftConfig.config[:database]).to eq old
+  end
+
+  it 'can unprotect a default protected value' do
+    FoodsoftConfig.config[:protected][:database] = false
+    old = FoodsoftConfig[:database]
+    FoodsoftConfig[:database] = name
+    expect(FoodsoftConfig[:database]).to eq name
+  end
+
+  describe 'can protect a value', type: :feature do
+    before do
+      FoodsoftConfig.config[:protected][:name] = true
+    end
+
+    it 'can protect a value' do
+      old_name = FoodsoftConfig[:name]
+      FoodsoftConfig[:name] = name
+      expect(FoodsoftConfig[:name]).to eq old_name
+    end
+
+    it 'and unprotect it again' do
+      old_name = FoodsoftConfig[:name]
+      FoodsoftConfig.config[:protected][:name] = false
+      FoodsoftConfig[:name] = name
+      expect(FoodsoftConfig[:name]).to eq name
+    end
+  end
+
+  describe 'has indifferent access', type: :feature do
+    it 'with symbol' do
+      FoodsoftConfig[:name] = name
+      expect(FoodsoftConfig[:name]).to eq FoodsoftConfig['name']
+    end
+
+    it 'with string' do
+      FoodsoftConfig['name'] = name
+      expect(FoodsoftConfig['name']).to eq FoodsoftConfig[:name]
+    end
+
+    it 'with nested symbol' do
+      FoodsoftConfig[:protected][:database] = true
+      expect(FoodsoftConfig[:protected]['database']).to eq FoodsoftConfig[:protected][:database]
+    end
+
+    it 'with nested string' do
+      FoodsoftConfig[:protected]['database'] = true
+      expect(FoodsoftConfig[:protected]['database']).to eq FoodsoftConfig[:protected][:database]
+    end
+  end
+
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 739df522..3b7389c0 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -35,6 +35,8 @@ RSpec.configure do |config|
   end
   config.after(:each) do
     DatabaseCleaner.clean
+    # Need to clear cache for RailsSettings::CachedSettings
+    Rails.cache.clear
   end
 
   # reload foodsoft configuration, so that tests can use FoodsoftConfig.config[:foo]=x