diff --git a/app/views/admin/configs/show.html.haml b/app/views/admin/configs/show.html.haml
index 671121cc..7f0e1842 100644
--- a/app/views/admin/configs/show.html.haml
+++ b/app/views/admin/configs/show.html.haml
@@ -1,6 +1,7 @@
 - title t('admin.configs.tabs.title'), false
 
-= simple_form_for :config, method: :patch do |f|
+-# disable validations, because browsers can't handle inputs hidden in another tab
+= simple_form_for :config, method: :patch, html: {novalidate: true} do |f|
 
   = render 'tabs', url: nil
 
diff --git a/lib/foodsoft_config.rb b/lib/foodsoft_config.rb
index 665abfaf..e3f47f66 100644
--- a/lib/foodsoft_config.rb
+++ b/lib/foodsoft_config.rb
@@ -225,6 +225,7 @@ class FoodsoftConfig
         currency_unit: '€',
         currency_space: true,
         foodsoft_url: 'https://github.com/foodcoops/foodsoft',
+        contact: {}, # avoid errors when undefined
         # The following keys cannot, by default, be set by foodcoops themselves.
         protected: {
           multi_coop_install: true,
diff --git a/spec/app_config.yml b/spec/app_config.yml
index 5da8aa3c..0bf51d41 100644
--- a/spec/app_config.yml
+++ b/spec/app_config.yml
@@ -8,13 +8,7 @@ default: &defaults
   multi_coop_install: false
   default_scope: 'f'
 
-
   name: FC Minimal
-  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