diff --git a/lib/active_model/validations/collection_items_validator/inner_validator_builder.rb b/lib/active_model/validations/collection_items_validator/inner_validator_builder.rb
index 46559ee..f89016a 100644
--- a/lib/active_model/validations/collection_items_validator/inner_validator_builder.rb
+++ b/lib/active_model/validations/collection_items_validator/inner_validator_builder.rb
@@ -14,7 +14,7 @@ def initialize(validator_name, options)
       end
 
       def build
-        validator_class.new **inner_options.merge(attributes: [:base])
+        validator_class.new **(inner_options.merge(attributes: [:base]))
       end
 
       private