diff --git a/app/models/spree/product_decorator.rb b/app/models/spree/product_decorator.rb
index 7682720708..7f84913d68 100644
--- a/app/models/spree/product_decorator.rb
+++ b/app/models/spree/product_decorator.rb
@@ -151,7 +151,7 @@ Spree::Product.class_eval do
     if variant_unit_changed?
       option_types.delete self.class.all_variant_unit_option_types
       option_types << variant_unit_option_type if variant_unit.present?
-      variants.each { |v| v.delete_unit_option_values }
+      variants_including_master.each { |v| v.delete_unit_option_values }
     end
   end
 
diff --git a/spec/models/spree/product_spec.rb b/spec/models/spree/product_spec.rb
index d42f811422..813a57558f 100644
--- a/spec/models/spree/product_spec.rb
+++ b/spec/models/spree/product_spec.rb
@@ -429,6 +429,16 @@ module Spree
             p.update_attributes!(variant_unit: 'volume', variant_unit_scale: 0.001)
           }.to change(v.option_values(true), :count).by(-1)
         end
+
+        it "removes the related option values from its master variant" do
+          ot = Spree::OptionType.find_by_name 'unit_weight'
+          p.master.update_attributes!(unit_value: 1)
+          p.reload
+
+          expect {
+            p.update_attributes!(variant_unit: 'volume', variant_unit_scale: 0.001)
+          }.to change(p.master.option_values(true), :count).by(-1)
+        end
       end
 
       describe "returning the variant unit option type" do