diff --git a/modules/cart/src/Form/AddToCartForm.php b/modules/cart/src/Form/AddToCartForm.php
index d546fa9..f055477 100644
--- a/modules/cart/src/Form/AddToCartForm.php
+++ b/modules/cart/src/Form/AddToCartForm.php
@@ -210,10 +210,16 @@ class AddToCartForm extends ContentEntityForm implements AddToCartFormInterface
     // Other submit handlers might need the cart ID.
     $form_state->set('cart_id', $cart->id());
 
-    drupal_set_message($this->t('@entity added to @cart-link.', [
+    $message = $this->t('@entity added to @cart-link.', [
       '@entity' => $purchased_entity->label(),
       '@cart-link' => Link::createFromRoute($this->t('your cart', [], ['context' => 'cart link']), 'commerce_cart.page')->toString(),
-    ]));
+    ]);
+
+    \Drupal::moduleHandler()->alter("commerce_add_to_cart_message", $message, $cart, $purchased_entity);
+    // Let people know about the outcome.
+    if (isset($message) && !empty($message)){
+      drupal_set_message($message);
+    }
   }
 
   /**