diff --git a/src/Collection.php b/src/Collection.php
index 5d669ae3..90fbefaf 100644
--- a/src/Collection.php
+++ b/src/Collection.php
@@ -31,9 +31,9 @@ class Collection implements CollectionInterface, IteratorAggregate, Countable
     /**
      * Returns Iterator
      *
-     * @return array
+     * @return \Traversable
      */
-    public function getIterator()
+    public function getIterator(): \Traversable
     {
         return new ArrayIterator($this->items);
     }
diff --git a/src/Drivers/Gd/Modifiers/BrightnessModifier.php b/src/Drivers/Gd/Modifiers/BrightnessModifier.php
index ee306bf0..443a41b6 100644
--- a/src/Drivers/Gd/Modifiers/BrightnessModifier.php
+++ b/src/Drivers/Gd/Modifiers/BrightnessModifier.php
@@ -15,7 +15,7 @@ class BrightnessModifier implements ModifierInterface
     public function apply(ImageInterface $image): ImageInterface
     {
         foreach ($image as $frame) {
-            imagefilter($frame->getCore(), IMG_FILTER_BRIGHTNESS, ($this->level * 2.55));
+            imagefilter($frame->getCore(), IMG_FILTER_BRIGHTNESS, intval($this->level * 2.55));
         }
 
         return $image;