diff --git a/app/models/calculator/weight.rb b/app/models/calculator/weight.rb
index cff4dba4fa..d5bf102c14 100644
--- a/app/models/calculator/weight.rb
+++ b/app/models/calculator/weight.rb
@@ -54,6 +54,8 @@ module Calculator
     #    Customer ends up getting 350mL (line_item.final_weight_volume) of wine
     #      that represent 2.8 (quantity_implied_in_final_weight_volume) glasses of wine
     def quantity_implied_in_final_weight_volume(line_item)
+      return line_item.quantity if line_item.variant.unit_value.zero?
+
       (1.0 * line_item.final_weight_volume / line_item.variant.unit_value).round(3)
     end
 
diff --git a/spec/models/calculator/weight_spec.rb b/spec/models/calculator/weight_spec.rb
index cebaba31cd..8155456bf0 100644
--- a/spec/models/calculator/weight_spec.rb
+++ b/spec/models/calculator/weight_spec.rb
@@ -163,19 +163,11 @@ describe Calculator::Weight do
 
     before { subject.set_preference(:per_kg, 5) }
 
-    it "returns NaN if variant.weight is not present" do
-      expect(subject.compute(line_item1).nan?).to be_truthy
-    end
-
-    xit "uses zero weight if variant.weight is not present" do
+    it "uses zero weight if variant.weight is not present" do
       expect(subject.compute(line_item1)).to eq 0
     end
 
-    it "returns NaN if variant.weight is present" do
-      expect(subject.compute(line_item2).nan?).to be_truthy
-    end
-
-    xit "uses the variant weight if variant.weight is present" do
+    it "uses the variant weight if variant.weight is present" do
       expect(subject.compute(line_item2)).to eq 50.0
     end
   end