diff --git a/src/BigCommerce/ResourceModels/Catalog/Product/ComplexRuleConditions.php b/src/BigCommerce/ResourceModels/Catalog/Product/ComplexRuleConditions.php
index 2b488fe..dbbd599 100644
--- a/src/BigCommerce/ResourceModels/Catalog/Product/ComplexRuleConditions.php
+++ b/src/BigCommerce/ResourceModels/Catalog/Product/ComplexRuleConditions.php
@@ -9,6 +9,6 @@ class ComplexRuleConditions extends ResourceModel
     public int $rule_id;
     public int $modifier_id;
     public int $modifier_value_id;
-    public array $variant_id;
+    public ?int $variant_id;
     public int $combination_id;
 }
diff --git a/src/BigCommerce/ResourceModels/Catalog/Product/PriceAdjuster.php b/src/BigCommerce/ResourceModels/Catalog/Product/PriceAdjuster.php
index c97ed1b..31b4793 100644
--- a/src/BigCommerce/ResourceModels/Catalog/Product/PriceAdjuster.php
+++ b/src/BigCommerce/ResourceModels/Catalog/Product/PriceAdjuster.php
@@ -11,4 +11,13 @@ class PriceAdjuster extends ResourceModel
 
     public string $adjuster;
     public float $adjuster_value;
+    
+    protected function beforeBuildObject(): void
+    {
+        if (!is_null($this->optionObject)) {
+            if(is_null($this->optionObject->adjuster)){
+                $this->optionObject->adjuster = self::ADJUSTER_FIXED;
+            }
+        }
+    }
 }
diff --git a/src/BigCommerce/ResourceModels/Catalog/Product/WeightAdjuster.php b/src/BigCommerce/ResourceModels/Catalog/Product/WeightAdjuster.php
index 26a2112..1961e31 100644
--- a/src/BigCommerce/ResourceModels/Catalog/Product/WeightAdjuster.php
+++ b/src/BigCommerce/ResourceModels/Catalog/Product/WeightAdjuster.php
@@ -6,6 +6,18 @@
 
 class WeightAdjuster extends ResourceModel
 {
+    public const ADJUSTER_RELATIVE = 'relative';
+    public const ADJUSTER_FIXED    = 'fixed';
+
     public string $adjuster;
     public float $adjuster_value;
+    
+    protected function beforeBuildObject(): void
+    {
+        if (!is_null($this->optionObject)) {
+            if(is_null($this->optionObject->adjuster)){
+                $this->optionObject->adjuster = self::ADJUSTER_FIXED;
+            }
+        }
+    }
 }
diff --git a/src/BigCommerce/ResourceModels/ResourceModel.php b/src/BigCommerce/ResourceModels/ResourceModel.php
index 12ab187..5e703a8 100644
--- a/src/BigCommerce/ResourceModels/ResourceModel.php
+++ b/src/BigCommerce/ResourceModels/ResourceModel.php
@@ -7,7 +7,7 @@
 
 abstract class ResourceModel implements JsonSerializable
 {
-    private ?stdClass $optionObject;
+    protected ?stdClass $optionObject;
 
     public function __construct(?stdClass $optionObject = null)
     {