diff --git a/app/models/concerns/node_properties.rb b/app/models/concerns/node_properties.rb
index ca92c7661..54c547e00 100644
--- a/app/models/concerns/node_properties.rb
+++ b/app/models/concerns/node_properties.rb
@@ -19,13 +19,13 @@ def self.included(base)
   end
 
   SERVICE_KEYS = %i[protocol port state product reason name version]
-  SERVICE_PROPERTIES = %i[services services_extras]
+  SERVICE_PROPERTIES = %w[services services_extras]
 
   # -------------------------------------------- Individual property management
   # Sets a property, storing value as Array when needed
   # and taking care of duplications
   def set_property(key, value)
-    if SERVICE_PROPERTIES.include?(key.to_sym) # let's get defensive
+    if SERVICE_PROPERTIES.include?(key.to_s) # let's get defensive
       raise ArgumentError, 'don\'t use set_property for :services or '\
                            ':services_extras, use set_service instead'
     end