diff --git a/src/VariantData.php b/src/VariantData.php
index 6100ad7..89f8b60 100644
--- a/src/VariantData.php
+++ b/src/VariantData.php
@@ -20,6 +20,13 @@ public function getProductId(): string
         return $this->productId;
     }
 
+    public function equals($other): bool
+    {
+        return $other instanceof VariantData
+            && parent::equals($other)
+            && $this->productId === $other->productId;
+    }
+
     public function toJson(): array
     {
         $json = parent::toJson();
diff --git a/test/unit/VariantTest.php b/test/unit/VariantTest.php
index 4483e7b..fb43262 100644
--- a/test/unit/VariantTest.php
+++ b/test/unit/VariantTest.php
@@ -67,4 +67,16 @@ public function testVariantIdSameAsProductIdThrows()
     {
         VariantData::of('foo', 'foo');
     }
+
+    public function testEquals()
+    {
+        $product1 = VariantData::of('foo', 'bar')
+            ->withAttributeValue(AttributeValue::of('colour', 'red'));
+        $product2 = VariantData::of('foo', 'bar')
+            ->withAttributeValue(AttributeValue::of('colour', 'red'));
+        self::assertTrue($product1->equals($product2));
+        $product3 = VariantData::of('foo', 'baz')
+            ->withAttributeValue(AttributeValue::of('colour', 'red'));
+        self::assertFalse($product1->equals($product3));
+    }
 }