diff --git a/uc_cart/tests/uc_cart.test b/uc_cart/tests/uc_cart.test
index d96f837..5ec03b0 100644
--- a/uc_cart/tests/uc_cart.test
+++ b/uc_cart/tests/uc_cart.test
@@ -103,8 +103,7 @@ class UbercartCartCheckoutTestCase extends UbercartTestHelper {
 
     // Empty the cart.
     uc_cart_add_item($this->product->nid);
-    // @TODO: default to the current cart
-    uc_cart_empty(uc_cart_get_id());
+    uc_cart_empty();
 
     $items = uc_cart_get_contents();
     $this->assertEqual($items, array(), 'Cart is emptied correctly.');
diff --git a/uc_cart/uc_cart.module b/uc_cart/uc_cart.module
index e98c7e2..91226d5 100644
--- a/uc_cart/uc_cart.module
+++ b/uc_cart/uc_cart.module
@@ -893,7 +893,7 @@ function uc_cart_complete_sale($order, $login = FALSE) {
   $output = filter_xss_admin(implode(' ', $messages));
 
   // Empty that cart...
-  uc_cart_empty(uc_cart_get_id(FALSE));
+  uc_cart_empty();
 
   return array(
     '#theme' => 'uc_cart_complete_sale',
@@ -1252,10 +1252,12 @@ function uc_cart_update_item_object($cart) {
  * Empties a cart of its contents.
  *
  * @param $cart_id
- *   The ID of the cart.
+ *   The ID of the cart, or NULL to empty the current cart.
  */
-function uc_cart_empty($cart_id) {
-  if (is_null($cart_id) || empty($cart_id)) {
+function uc_cart_empty($cart_id = NULL) {
+  $cart_id = $cart_id ? $cart_id : uc_cart_get_id(FALSE);
+
+  if (!$cart_id) {
     return;
   }
 
diff --git a/uc_cart_links/uc_cart_links.pages.inc b/uc_cart_links/uc_cart_links.pages.inc
index 1e38cb7..2b511f8 100644
--- a/uc_cart_links/uc_cart_links.pages.inc
+++ b/uc_cart_links/uc_cart_links.pages.inc
@@ -156,7 +156,7 @@ function uc_cart_links_process($cart_actions) {
       case 'e':
       case 'E':
         if (variable_get('uc_cart_links_empty', TRUE)) {
-          uc_cart_empty(uc_cart_get_id());
+          uc_cart_empty();
         }
         break;