diff --git a/README.md b/README.md
index b0340e3..a8ceb0b 100644
--- a/README.md
+++ b/README.md
@@ -306,8 +306,8 @@ $cart->setTax($rowId, 21);
 You can use the `setGlobalTax()` method to change the tax rate for all items in the cart. New items will receive the setGlobalTax as well.
 
 ```php
-Cart::setGlobalDiscount(21);
-$cart->setGlobalDiscount(21);
+Cart::setGlobalTax(21);
+$cart->setGlobalTax(21);
 ```
 
 ### Cart::setGlobalDiscount($discountRate)
@@ -315,8 +315,8 @@ $cart->setGlobalDiscount(21);
 You can use the `setGlobalDiscount()` method to change the discount rate for all items in the cart. New items will receive the discount as well.
 
 ```php
-Cart::setGlobalDiscount(21);
-$cart->setGlobalDiscount(21);
+Cart::setGlobalDiscount(50);
+$cart->setGlobalDiscount(50);
 ```
 
 ### Cart::setDiscount($rowId, $taxRate)
diff --git a/composer.json b/composer.json
index daac79e..23a9b02 100644
--- a/composer.json
+++ b/composer.json
@@ -6,11 +6,13 @@
     "authors": [
         {
             "name": "Rob Gloudemans",
-            "email": "info@robgloudemans.nl"
+            "email": "info@robgloudemans.nl",
+            "homepage": "http://robgloudemans.nl/"
         },
         {
             "name": "Patrick Henninger",
-            "email": "privat@skyraptor.eu"
+            "email": "privat@skyraptor.eu",
+            "homepage": "https://skyraptor.eu/"
         }
     ],
     "require": {
diff --git a/src/Cart.php b/src/Cart.php
index 0e2269c..97097a0 100644
--- a/src/Cart.php
+++ b/src/Cart.php
@@ -110,7 +110,7 @@ class Cart
      *
      * @return \Gloudemans\Shoppingcart\CartItem
      */
-    public function add($id, $name = null, $qty = null, $price = null, $weight = null, array $options = [])
+    public function add($id, $name = null, $qty = null, $price = null, $weight = 0, array $options = [])
     {
         if ($this->isMulti($id)) {
             return array_map(function ($item) {
diff --git a/src/CartItem.php b/src/CartItem.php
index 0717ed7..16b448b 100644
--- a/src/CartItem.php
+++ b/src/CartItem.php
@@ -97,6 +97,9 @@ class CartItem implements Arrayable, Jsonable
         if (strlen($price) < 0 || !is_numeric($price)) {
             throw new \InvalidArgumentException('Please supply a valid price.');
         }
+        if (strlen($price) < 0 || !is_numeric($weight)) {
+            throw new \InvalidArgumentException('Please supply a valid weight.');
+        }
 
         $this->id = $id;
         $this->name = $name;
diff --git a/src/ShoppingcartServiceProvider.php b/src/ShoppingcartServiceProvider.php
index a26ef89..2e6b1b5 100644
--- a/src/ShoppingcartServiceProvider.php
+++ b/src/ShoppingcartServiceProvider.php
@@ -30,6 +30,6 @@ class ShoppingcartServiceProvider extends ServiceProvider
 
         $this->publishes([
             realpath(__DIR__.'/Database/migrations') => $this->app->databasePath().'/migrations',
-        ]);
+        ], 'migrations');
     }
 }
diff --git a/tests/CartTest.php b/tests/CartTest.php
index 8c278e5..fc8f6ab 100644
--- a/tests/CartTest.php
+++ b/tests/CartTest.php
@@ -264,6 +264,19 @@ class CartTest extends TestCase
         $cart->add(1, 'Some title', 1, 'invalid');
     }
 
+    /**
+     * @test
+     */
+    public function it_will_validate_the_weight()
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Please supply a valid weight');
+
+        $cart = $this->getCart();
+
+        $cart->add(1, 'Some title', 1, 10.00, 'invalid');
+    }
+
     /** @test */
     public function it_will_update_the_cart_if_the_item_already_exists_in_the_cart()
     {