diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f00fdeb..5e0c7c4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,6 +10,14 @@ test_roles:
   tags:
     - docker
 
+test_custom_grains:
+  stage: test
+  before_script:
+    - zypper -qn in --no-recommends python3 python3-PyYAML
+  script: bin/test_custom_grains.py
+  tags:
+    - docker
+
 test_show_highstate:
   stage: test
   before_script:
diff --git a/bin/test_custom_grains.py b/bin/test_custom_grains.py
new file mode 100755
index 0000000..0288baa
--- /dev/null
+++ b/bin/test_custom_grains.py
@@ -0,0 +1,61 @@
+#!/usr/bin/python3
+
+# Validates if the pillar/id/$FQDN.sls has correct custom grains
+
+import yaml
+import os
+import sys
+
+
+def error_msg(sls, key, valid_values):
+    if type(valid_values) == str:
+        msg = ' is'
+        result = valid_values
+    else:
+        msg = 's are'
+        result = ', '.join(valid_values)
+    print('pillar/id/%s has invalid value for the "%s" key. Valid value%s: %s' % (sls, key, msg, result))
+    return 1
+
+
+def test_custom_grain(mygrains, sls, key, valid_values, status):
+    try:
+        value = mygrains[key]
+    except KeyError:
+        print('pillar/id/%s is missing the "%s" key' % (sls, key))
+        return 1
+
+    if type(valid_values) == str:
+        if value != valid_values:
+            status = error_msg(sls, key, valid_values)
+    else:
+        if value not in valid_values:
+            status = error_msg(sls, key, valid_values)
+
+    return status
+
+
+status = 0
+
+with open('pillar/valid_custom_grains.yaml', 'r') as f:
+    VALID_CUSTOM_GRAINS = yaml.load(f)
+
+valid_global_grains = VALID_CUSTOM_GRAINS['global']
+all_localized_grains = VALID_CUSTOM_GRAINS['localized']
+
+all_ids = sorted(os.listdir('pillar/id'))
+for sls in all_ids:
+    with open("pillar/id/%s" % sls) as f:
+        mygrains = yaml.load(f)['grains']
+
+        for key, valid_values in valid_global_grains.items():
+            status = test_custom_grain(mygrains, sls, key, valid_values, status)
+
+        try:
+            valid_localized_grains = all_localized_grains[mygrains['country']]
+            for key, valid_values in valid_localized_grains.items():
+                status = test_custom_grain(mygrains, sls, key, valid_values, status)
+        except KeyError:
+            status = error_msg(sls, 'country', all_localized_grains.keys())
+
+sys.exit(status)
diff --git a/pillar/macros.jinja b/pillar/macros.jinja
index 3a7579c..c234db6 100644
--- a/pillar/macros.jinja
+++ b/pillar/macros.jinja
@@ -5,3 +5,18 @@
     {% endif %}
   {%- endfor %}
 {%- endmacro %}
+
+{%- macro valid_virt_cluster() -%}
+  {%- import_yaml "valid_custom_grains.yaml" as valid_custom_grains -%}
+  {%- set valid_virt_cluster = [] -%}
+  {%- for country, data in valid_custom_grains['localized'].items() -%}
+    {%- if data['virt_cluster'] is iterable and data['virt_cluster'] is not string -%}
+      {%- for item in data['virt_cluster'] -%}
+        {%- do valid_virt_cluster.append(item) -%}
+      {%- endfor -%}
+    {%- else -%}
+      {%- do valid_virt_cluster.append(data['virt_cluster']) -%}
+    {%- endif -%}
+  {%- endfor -%}
+  {{ valid_virt_cluster }}
+{%- endmacro -%}
diff --git a/pillar/top.sls b/pillar/top.sls
index ae95529..eab9795 100644
--- a/pillar/top.sls
+++ b/pillar/top.sls
@@ -1,4 +1,5 @@
 {% from "macros.jinja" import include_optional with context %}
+{% from "macros.jinja" import valid_virt_cluster with context %}
 {% set country = salt['grains.get']('country') %}
 {% set domain = salt['grains.get']('domain') %}
 {% set id = salt['grains.get']('id') %}
@@ -17,7 +18,7 @@ production:
     - match: grain
     {{ include_optional("role/{0}".format(role)) }}
   {% endfor %}
-  {% if virt_cluster in ['atreju', 'bryce'] %}
+  {% if virt_cluster in valid_virt_cluster() %}
   'virt_cluster:{{ virt_cluster }}':
     - match: grain
     - virt_cluster.{{ virt_cluster }}
diff --git a/pillar/valid_custom_grains.yaml b/pillar/valid_custom_grains.yaml
new file mode 100644
index 0000000..285daa3
--- /dev/null
+++ b/pillar/valid_custom_grains.yaml
@@ -0,0 +1,10 @@
+---
+global:
+  salt_cluster: opensuse
+localized:
+  de:
+    city: nuremberg
+    virt_cluster: atreju
+  us:
+    city: provo
+    virt_cluster: bryce