diff --git a/lib/data_mapper/relationship/builder/has.rb b/lib/data_mapper/relationship/builder/has.rb
index <HASH>..<HASH> 100644
--- a/lib/data_mapper/relationship/builder/has.rb
+++ b/lib/data_mapper/relationship/builder/has.rb
@@ -38,6 +38,8 @@ module DataMapper
 
           options = options_class.new(name, source.model, target_model, options)
 
+          options.validate
+
           @relationship = options.type.new(options)
         end
Also perform option validation in Builder::Has