diff --git a/bin/test_custom_grains.py b/bin/test_custom_grains.py
index fe00d60..5e33d91 100755
--- a/bin/test_custom_grains.py
+++ b/bin/test_custom_grains.py
@@ -30,7 +30,7 @@ def test_custom_grain(mygrains, sls, key, valid_values, status):
         if value != valid_values:
             status = error_msg(sls, key, valid_values)
     else:
-        if value not in valid_values:
+        if valid_values and value not in valid_values:
             status = error_msg(sls, key, valid_values)
 
     return status
diff --git a/pillar/valid_custom_grains.yaml b/pillar/valid_custom_grains.yaml
index 285daa3..1494c7b 100644
--- a/pillar/valid_custom_grains.yaml
+++ b/pillar/valid_custom_grains.yaml
@@ -1,5 +1,6 @@
 ---
 global:
+  hostusage: []
   salt_cluster: opensuse
 localized:
   de: