diff --git a/includes/commerce_coupon.checkout_pane.inc b/includes/commerce_coupon.checkout_pane.inc
index fd1d8fb..e42927a 100644
--- a/includes/commerce_coupon.checkout_pane.inc
+++ b/includes/commerce_coupon.checkout_pane.inc
@@ -97,8 +97,12 @@ function commerce_coupon_pane_checkout_form($form, &$form_state, $checkout_pane,
     if (!$error) {
       // If a coupon was invalidated during the cart refresh (e.g. if its
       // discounts failed their conditions), an error message will have been
-      // set.
-      $error = &drupal_static('commerce_coupon_error_' . strtolower($code));
+      // set.  We check for errors from both coupon conditions as well as
+      // discount conditions.
+      $error = trim(implode(' ', array(
+        drupal_static('commerce_coupon_error_' . strtolower($code)),
+        drupal_static('commerce_coupon_error_discount_conditions'),
+      )));
     }
 
     if (!$error) {