diff --git a/src/platform/magento1/tax.js b/src/platform/magento1/tax.js
index 9bb1b04b..5d953cdf 100644
--- a/src/platform/magento1/tax.js
+++ b/src/platform/magento1/tax.js
@@ -39,10 +39,10 @@ class TaxProxy extends AbstractTaxProxy {
         taxCountry = this._config.tax.defaultCountry
       }
     }
-    if (sourcePriceInclTax === null) {
+    if (sourcePriceInclTax == null) {
       sourcePriceInclTax = this._config.tax.sourcePriceIncludesTax
     }
-    if (finalPriceInclTax === null) {
+    if (finalPriceInclTax == null) {
       finalPriceInclTax = this._config.tax.finalPriceIncludesTax
     }
     this._deprecatedPriceFieldsSupport = this._config.tax.deprecatedPriceFieldsSupport
diff --git a/src/platform/magento2/tax.js b/src/platform/magento2/tax.js
index 175cd456..089fd0a0 100644
--- a/src/platform/magento2/tax.js
+++ b/src/platform/magento2/tax.js
@@ -38,10 +38,10 @@ class TaxProxy extends AbstractTaxProxy {
         taxCountry = this._config.tax.defaultCountry
       }
     }
-    if (sourcePriceInclTax === null) {
+    if (sourcePriceInclTax == null) {
       sourcePriceInclTax = this._config.tax.sourcePriceIncludesTax
     }
-    if (finalPriceInclTax === null) {
+    if (finalPriceInclTax == null) {
       finalPriceInclTax = this._config.tax.finalPriceIncludesTax
     }
     this._deprecatedPriceFieldsSupport = this._config.tax.deprecatedPriceFieldsSupport