diff --git a/src/Casts/PurifyHtmlOnGet.php b/src/Casts/PurifyHtmlOnGet.php
index bfa2138..84115f4 100644
--- a/src/Casts/PurifyHtmlOnGet.php
+++ b/src/Casts/PurifyHtmlOnGet.php
@@ -15,10 +15,14 @@ class PurifyHtmlOnGet extends Caster implements CastsAttributes
      * @param mixed                               $value
      * @param array                               $attributes
      *
-     * @return string|array
+     * @return string|array|null
      */
     public function get($model, $key, $value, $attributes)
     {
+        if (is_null($value)) {
+            return null;
+        }
+
         return Purify::config($this->config)->clean($value);
     }
 
@@ -30,7 +34,7 @@ public function get($model, $key, $value, $attributes)
      * @param mixed                               $value
      * @param array                               $attributes
      *
-     * @return array|string
+     * @return array|string|null
      */
     public function set($model, $key, $value, $attributes)
     {
diff --git a/src/Casts/PurifyHtmlOnSet.php b/src/Casts/PurifyHtmlOnSet.php
index a66cea9..a2d99f1 100644
--- a/src/Casts/PurifyHtmlOnSet.php
+++ b/src/Casts/PurifyHtmlOnSet.php
@@ -15,7 +15,7 @@ class PurifyHtmlOnSet extends Caster implements CastsAttributes
      * @param mixed                               $value
      * @param array                               $attributes
      *
-     * @return string|array
+     * @return string|array|null
      */
     public function get($model, string $key, $value, array $attributes)
     {
@@ -30,10 +30,14 @@ public function get($model, string $key, $value, array $attributes)
      * @param mixed                               $value
      * @param array                               $attributes
      *
-     * @return array|string
+     * @return array|string|null
      */
     public function set($model, string $key, $value, array $attributes)
     {
+        if (is_null($value)) {
+            return null;
+        }
+
         return Purify::config($this->config)->clean($value);
     }
 }
diff --git a/tests/CastsTest.php b/tests/CastsTest.php
index 3174893..b0061fb 100644
--- a/tests/CastsTest.php
+++ b/tests/CastsTest.php
@@ -36,6 +36,14 @@ public function test_purifies_on_get_with_custom_config()
         $this->assertEquals('<p>Test<span>bar</span></p>', $model->body);
     }
 
+    public function test_returns_null_on_get_when_value_is_null()
+    {
+        $model = new PurifyingDefaultOnGetModel();
+        $model->body = null;
+
+        $this->assertNull($model->body);
+    }
+
     public function test_purifies_on_set_with_default_config()
     {
         $this->app['config']->set('purify.configs.default', [
@@ -59,6 +67,14 @@ public function test_purifies_on_set_with_custom_config()
 
         $this->assertEquals('<p>Test<span>bar</span></p>', $model->getAttributes()['body']);
     }
+
+    public function test_sets_null_on_set_when_value_is_null()
+    {
+        $model = new PurifyingDefaultOnSetModel();
+        $model->body = null;
+
+        $this->assertNull($model->getAttributes()['body']);
+    }
 }
 
 class PurifyingDefaultOnGetModel extends Model