diff --git a/Method.php b/Method.php
index 5c9268f..2ddaab3 100644
--- a/Method.php
+++ b/Method.php
@@ -205,12 +205,16 @@ protected function amountFactor() {return 1;}
 	 *
 	 * https://mage2.pro/t/2686
 	 *
+	 * 2017-04-15
+	 * The «USD» currency could be not set up in the store,
+	 * so use @uses df_currency_convert_safe() to get rid from a failure like «Undefined rate from "AUD-USD"».
+	 *
 	 * @see \Df\Payment\Method::amountLimits()
 	 * @used-by \Df\Payment\Method::isAvailable()
 	 * @return \Closure
 	 */
 	protected function amountLimits() {return function($c) {return [
-		df_currency_convert(1, 'USD', $c), null
+		df_currency_convert_safe(1, 'USD', $c), null
 	];};}
 
 	/**
diff --git a/README.md b/README.md
index 7101331..605a400 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,7 @@ I provide the [**customization service**](https://mage2.pro/t/2020) for my payme
 - «[**Login with Amazon**](https://mage2.pro/c/extensions/amazon-login)» (a single sign-on extension). 
 - «[**Backend Login with Google Account**](https://mage2.pro/c/extensions/google-backend-login)» (a single sign-on extension for the Magento 2 backend). 
 - «[**Facebook Login**](https://mage2.pro/c/extensions/facebook-login)» (a single sign-on extension).
-- «[**Blackbaud NetCommunity**](https://mage2.pro/c/extensions/blackbaud-netcommunity)» (an  integration with an online fundraising software).  
+- «[**Blackbaud NetCommunity**](https://mage2.pro/c/extensions/blackbaud-netcommunity)» (an integration with an online fundraising software).  
 - «[**Markdown Editor**](https://mage2.pro/c/extensions/markdown)» (an alternative content editor for the Magento 2 backend).
 - «[**Twitter Timeline**](https://mage2.pro/c/extensions/twitter-timeline)» (shows your latest tweets in your store's frontend sidebar).
 - «[**Facebook Like & Share**](https://mage2.pro/c/extensions/facebook-like)» (shows the Facebook's «Like» and «Share» buttons on the frontend product pages).
diff --git a/composer.json b/composer.json
index ab483ee..283882b 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
 	"name": "mage2pro/2checkout"
-	,"version": "1.4.6"
+	,"version": "1.4.7"
 	,"description": "The «2Checkout» payment extension for Magento 2."
 	,"type": "magento2-module"
 	,"homepage": "https://mage2.pro/c/extensions/2checkout"
@@ -11,7 +11,7 @@
 		"homepage": "https://mage2.pro/users/dmitry_fedyuk",
 		"role": "Developer"
 	}]
-	,"require": {"mage2pro/core": ">=2.4.45", "2checkout/2checkout-php": "*"}
+	,"require": {"mage2pro/core": ">=2.4.56", "2checkout/2checkout-php": "*"}
 	,"autoload": {"files": ["registration.php"], "psr-4": {"Dfe\\TwoCheckout\\": ""}}
 	,"keywords": [
 		"2Checkout"