diff --git a/db/migrate/20210202052337_migrate_variant_unit_values.rb b/db/migrate/20210202052337_migrate_variant_unit_values.rb
new file mode 100644
index 0000000000..9c6cf46a2e
--- /dev/null
+++ b/db/migrate/20210202052337_migrate_variant_unit_values.rb
@@ -0,0 +1,27 @@
+class MigrateVariantUnitValues < ActiveRecord::Migration
+  def up
+    Spree::Variant.where(unit_value: [nil, Float::NAN]).find_each do |variant|
+      variant.unit_value = 1
+      variant.save
+    end
+    Spree::Variant.where(weight: [nil, Float::NAN]).find_each do |variant|
+      variant.weight = 0
+      variant.save
+    end
+    change_column_null :spree_variants, :unit_value, false, 1
+    change_column_null :spree_variants, :weight, false, 0.0
+    change_column_default :spree_variants, :unit_value, 1
+    change_column_default :spree_variants, :weight, 0.0
+    execute "ALTER TABLE spree_variants ADD CONSTRAINT check_unit_value_for_nan CHECK (unit_value <> 'NaN')"
+    execute "ALTER TABLE spree_variants ADD CONSTRAINT check_weight_for_nan CHECK (weight <> 'NaN')"
+  end
+
+  def down
+    change_column_null :spree_variants, :unit_value, true
+    change_column_null :spree_variants, :weight, true
+    change_column_default :spree_variants, :unit_value, nil
+    change_column_default :spree_variants, :weight, nil
+    execute "ALTER TABLE spree_variants DROP CONSTRAINT check_unit_value_for_nan"
+    execute "ALTER TABLE spree_variants DROP CONSTRAINT check_weight_for_nan"
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index a5b4c1c42b..aa00312da6 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,6 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
+
 ActiveRecord::Schema.define(version: 20210203215049) do
 
   # These are extensions that must be enabled in order to support this database
@@ -1061,7 +1062,7 @@ ActiveRecord::Schema.define(version: 20210203215049) do
 
   create_table "spree_variants", force: :cascade do |t|
     t.string   "sku",              limit: 255,                         default: "",    null: false
-    t.decimal  "weight",                       precision: 8, scale: 2
+    t.decimal  "weight",                       precision: 8, scale: 2, default: 0.0,   null: false
     t.decimal  "height",                       precision: 8, scale: 2
     t.decimal  "width",                        precision: 8, scale: 2
     t.decimal  "depth",                        precision: 8, scale: 2
@@ -1071,7 +1072,7 @@ ActiveRecord::Schema.define(version: 20210203215049) do
     t.decimal  "cost_price",                   precision: 8, scale: 2
     t.integer  "position"
     t.string   "cost_currency",    limit: 255
-    t.float    "unit_value"
+    t.float    "unit_value",                                           default: 1.0,   null: false
     t.string   "unit_description", limit: 255,                         default: ""
     t.string   "display_name",     limit: 255
     t.string   "display_as",       limit: 255
diff --git a/spec/models/spree/variant_spec.rb b/spec/models/spree/variant_spec.rb
index 5ef2d0637f..cfd0d41d8b 100644
--- a/spec/models/spree/variant_spec.rb
+++ b/spec/models/spree/variant_spec.rb
@@ -637,7 +637,7 @@ module Spree
       describe "setting the variant's weight from the unit value" do
         it "sets the variant's weight when unit is weight" do
           p = create(:simple_product, variant_unit: 'volume')
-          v = create(:variant, product: p, weight: nil)
+          v = create(:variant, product: p, weight: 0)
 
           p.update! variant_unit: 'weight', variant_unit_scale: 1
           v.update! unit_value: 10, unit_description: 'foo'