diff --git a/app/code/core/Mage/SalesRule/Model/Validator.php b/app/code/core/Mage/SalesRule/Model/Validator.php
index 033beb4dc48..32589269987 100644
--- a/app/code/core/Mage/SalesRule/Model/Validator.php
+++ b/app/code/core/Mage/SalesRule/Model/Validator.php
@@ -179,7 +179,12 @@ protected function _canProcessRule($rule, $address)
                         return false;
                     }
                     // check coupon expiration
-                    if ($coupon->hasExpirationDate() && ($coupon->getExpirationDate() < Mage::getModel('core/date')->date())) {
+                    $couponExpirationDay = null;
+                    if ($coupon->hasExpirationDate()) {
+                        $couponExpirationDay = Mage::getModel('core/date')->date(Varien_Date::DATE_PHP_FORMAT, $coupon->getExpirationDate());
+                    }
+                    $today = Mage::getModel('core/date')->date(Varien_Date::DATE_PHP_FORMAT);
+                    if ($couponExpirationDay !== null && ($couponExpirationDay < $today)) {
                         $rule->setIsValidForAddress($address, false);
                         return false;
                     }