diff --git a/includes/admin/class-wc-payment-discounts-admin.php b/includes/admin/class-wc-payment-discounts-admin.php
index 29ea31a..11c68b9 100644
--- a/includes/admin/class-wc-payment-discounts-admin.php
+++ b/includes/admin/class-wc-payment-discounts-admin.php
@@ -18,11 +18,6 @@ public function __construct() {
 		// Register plugin settings.
 		add_action( 'admin_init', array( $this, 'register_settings' ) );
 
-		// Need update message.
-		if ( defined( 'WOOCOMMERCE_VERSION' ) && ! version_compare( WOOCOMMERCE_VERSION, '2.0', '>=' ) ) {
-			add_action( 'admin_notices', array( $this, 'woocommerce_need_update' ) );
-		}
-
 		$this->maybe_update();
 	}
 
@@ -93,22 +88,11 @@ public function validate_settings( $options ) {
 	 * @return string Settings page content.
 	 */
 	public function display_plugin_admin_page() {
-		global $woocommerce;
-
 		$settings         = get_option( 'woocommerce_payment_discounts' );
-		$payment_gateways = $woocommerce->payment_gateways->payment_gateways();
+		$payment_gateways = WC()->payment_gateways->payment_gateways();
 
 		include_once 'views/html-admin-settings.php';
 	}
-
-	/**
-	 * WooCommerce need update.
-	 *
-	 * @return string Admin notice.
-	 */
-	public function woocommerce_need_update() {
-		echo '<div class="error"><p>' . __( '<strong>WooCommerce Discounts Per Payment Method</strong> works only with WooCommerce 2.0 or higher, please, upgrade you WooCommerce!', 'woocommerce-payment-discounts' ) . '</p></div>';
-	}
 }
 
 new WC_Payment_Discounts_Admin();
diff --git a/includes/class-wc-payment-discounts-add-discount.php b/includes/class-wc-payment-discounts-add-discount.php
index edcd767..3a95f2b 100644
--- a/includes/class-wc-payment-discounts-add-discount.php
+++ b/includes/class-wc-payment-discounts-add-discount.php
@@ -87,7 +87,7 @@ public function payment_method_title( $title, $id ) {
 			if ( strstr( $discount, '%' ) ) {
 				$value = $discount;
 			} else {
-				$value = woocommerce_price( $discount );
+				$value = wc_price( $discount );
 			}
 
 			$title .= ' <small>(' . sprintf( __( '%s off', 'woocommerce-payment-discounts' ), $value ) . ')</small>';
@@ -106,20 +106,18 @@ public function add_discount( $cart ) {
 			return;
 		}
 
-		global $woocommerce;
-
 		// Gets the settings.
 		$gateways = get_option( 'woocommerce_payment_discounts' );
 
-		if ( isset( $gateways[ $woocommerce->session->chosen_payment_method ] ) ) {
+		if ( isset( $gateways[ WC()->session->chosen_payment_method ] ) ) {
 			// Gets the gateway discount.
-			$value = $gateways[ $woocommerce->session->chosen_payment_method ];
+			$value = $gateways[ WC()->session->chosen_payment_method ];
 
 			if ( apply_filters( 'wc_payment_discounts_apply_discount', 0 < $value, $cart ) ) {
 
 				// Gets the gateway data.
-				$payment_gateways = $woocommerce->payment_gateways->payment_gateways();
-				$gateway          = $payment_gateways[ $woocommerce->session->chosen_payment_method ];
+				$payment_gateways = WC()->payment_gateways->payment_gateways();
+				$gateway          = $payment_gateways[ WC()->session->chosen_payment_method ];
 
 				// Generate the discount amount and title.
 				$discount_name = $this->discount_name( $value, $gateway );
diff --git a/uninstall.php b/uninstall.php
index 7d292aa..c7608e3 100644
--- a/uninstall.php
+++ b/uninstall.php
@@ -4,10 +4,6 @@
     exit;
 }
 
-// Delete old options.
-delete_option( 'wcpaydisc_settings' );
-delete_option( 'wcpaydisc_gateways' );
-
 // Delete plugin options.
 delete_option( 'woocommerce_payment_discounts' );
 delete_option( 'woocommerce_payment_discounts_version' );
diff --git a/woocommerce-payment-discounts.php b/woocommerce-payment-discounts.php
index 744f59b..34d0010 100644
--- a/woocommerce-payment-discounts.php
+++ b/woocommerce-payment-discounts.php
@@ -44,7 +44,7 @@ private function __construct() {
 		// Load plugin text domain.
 		add_action( 'init', array( $this, 'load_plugin_textdomain' ) );
 
-		if ( function_exists( 'WC' ) ) {
+		if ( defined( 'WC_VERSION' ) && ! version_compare( WC_VERSION, '2.1', '>=' ) ) {
 			if ( is_admin() && ( ! defined( 'DOING_AJAX' ) || ! DOING_AJAX ) ) {
 				$this->admin_includes();
 			}
@@ -115,7 +115,7 @@ public function load_plugin_textdomain() {
 	 * @return string Admin notice.
 	 */
 	public function woocommerce_is_missing_notice() {
-		echo '<div class="error"><p>' . sprintf( __( '<strong>WooCommerce Discounts Per Payment Method</strong> depends on the last version of %s to work!', 'woocommerce-payment-discounts' ), '<a href="http://wordpress.org/extend/plugins/woocommerce/">' . __( 'WooCommerce', 'woocommerce-payment-discounts' ) . '</a>' ) . '</p></div>';
+		echo '<div class="error"><p><strong>' . __( 'WooCommerce Discounts Per Payment Method', 'woocommerce-payment-discounts' ) . '</strong> ' . sprintf( __( 'works only with %s 2.1 or higher, please install or upgrade your installation!', 'woocommerce-payment-discounts' ), '<a href="http://wordpress.org/plugins/woocommerce/">' . __( 'WooCommerce', 'woocommerce-payment-discounts' ) . '</a>' ) . '</p></div>';
 	}
 }