diff --git a/src/Illuminate/Database/Eloquent/Casts/AsArrayObject.php b/src/Illuminate/Database/Eloquent/Casts/AsArrayObject.php
index 8d950e2daff4..a939e8acdbdb 100644
--- a/src/Illuminate/Database/Eloquent/Casts/AsArrayObject.php
+++ b/src/Illuminate/Database/Eloquent/Casts/AsArrayObject.php
@@ -18,7 +18,7 @@ public static function castUsing(array $arguments)
         return new class implements CastsAttributes {
             public function get($model, $key, $value, $attributes)
             {
-                return new ArrayObject(json_decode($attributes[$key], true));
+                return isset($attributes[$key]) ? new ArrayObject(json_decode($attributes[$key], true)) : null;
             }
 
             public function set($model, $key, $value, $attributes)
diff --git a/src/Illuminate/Database/Eloquent/Casts/AsCollection.php b/src/Illuminate/Database/Eloquent/Casts/AsCollection.php
index e96834f6e4d3..c2d567b504f7 100644
--- a/src/Illuminate/Database/Eloquent/Casts/AsCollection.php
+++ b/src/Illuminate/Database/Eloquent/Casts/AsCollection.php
@@ -19,7 +19,7 @@ public static function castUsing(array $arguments)
         return new class implements CastsAttributes {
             public function get($model, $key, $value, $attributes)
             {
-                return new Collection(json_decode($attributes[$key], true));
+                return isset($attributes[$key]) ? new Collection(json_decode($attributes[$key], true)) : null;
             }
 
             public function set($model, $key, $value, $attributes)