diff --git a/engines/dfc_provider/app/services/quantitative_value_builder.rb b/engines/dfc_provider/app/services/quantitative_value_builder.rb
index 0004c80703..7013063062 100644
--- a/engines/dfc_provider/app/services/quantitative_value_builder.rb
+++ b/engines/dfc_provider/app/services/quantitative_value_builder.rb
@@ -34,6 +34,8 @@ class QuantitativeValueBuilder < DfcBuilder
       case quantity.unit
       when quantity_unit.LITRE
         ["volume", "liter", 1]
+      when quantity_unit.MILLIGRAM
+        ["weight", "mg", 0.001]
       when quantity_unit.GRAM
         ["weight", "gram", 1]
       when quantity_unit.KILOGRAM
diff --git a/engines/dfc_provider/spec/services/quantitative_value_builder_spec.rb b/engines/dfc_provider/spec/services/quantitative_value_builder_spec.rb
index 60528f0ae6..aa2f7a9142 100644
--- a/engines/dfc_provider/spec/services/quantitative_value_builder_spec.rb
+++ b/engines/dfc_provider/spec/services/quantitative_value_builder_spec.rb
@@ -89,5 +89,19 @@ describe QuantitativeValueBuilder do
       expect(product.variant_unit_scale).to eq 1_000
       expect(product.unit_value).to eq 4_000
     end
+
+    it "knows metric units with a small scale" do
+      quantity = DataFoodConsortium::Connector::QuantitativeValue.new(
+        unit: quantity_unit.MILLIGRAM,
+        value: 5,
+      )
+
+      builder.apply(quantity, product)
+
+      expect(product.variant_unit).to eq "weight"
+      expect(product.variant_unit_name).to eq "mg"
+      expect(product.variant_unit_scale).to eq 0.001
+      expect(product.unit_value).to eq 0.005
+    end
   end
 end