diff --git a/composer.json b/composer.json
index 6b1363f..632a270 100644
--- a/composer.json
+++ b/composer.json
@@ -1,32 +1,33 @@
 {
-    "name": "mathieutu/laravel-json-syncer",
-    "description": "Export and import your models to/from JSON",
-    "type": "package",
-    "require": {
-        "php": ">=7.0",
-        "illuminate/support": "^5.4",
-        "illuminate/database": "^5.4"
-    },
-    "require-dev": {
-        "phpunit/phpunit": "~5.7",
-        "orchestra/testbench": "~3.0"
-    },
-    "license": "MIT",
-    "authors": [
-        {
-            "name": "Mathieu TUDISCO",
-            "email": "dev@mathieutu.ovh"
-        }
-    ],
-    "autoload": {
-        "psr-4": {
-            "MathieuTu\\JsonSyncer\\": "src/"
-        }
-    },
-    "autoload-dev": {
-        "psr-4": {
-            "MathieuTu\\JsonSyncer\\Tests\\": "tests/"
-        }
-    },
-    "minimum-stability": "stable"
+  "name": "mathieutu/laravel-json-syncer",
+  "description": "Export and import your models to/from JSON",
+  "type": "package",
+  "require": {
+    "php": ">=7.0",
+    "illuminate/support": "^5.4",
+    "illuminate/database": "^5.4",
+    "ext-json": "*"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "~5.7",
+    "orchestra/testbench": "~3.0"
+  },
+  "license": "MIT",
+  "authors": [
+    {
+      "name": "Mathieu TUDISCO",
+      "email": "dev@mathieutu.ovh"
+    }
+  ],
+  "autoload": {
+    "psr-4": {
+      "MathieuTu\\JsonSyncer\\": "src/"
+    }
+  },
+  "autoload-dev": {
+    "psr-4": {
+      "MathieuTu\\JsonSyncer\\Tests\\": "tests/"
+    }
+  },
+  "minimum-stability": "stable"
 }
diff --git a/src/Helpers/JsonImporter.php b/src/Helpers/JsonImporter.php
index 0b0c0fb..8a9e5e1 100644
--- a/src/Helpers/JsonImporter.php
+++ b/src/Helpers/JsonImporter.php
@@ -28,11 +28,8 @@ public function import($objects)
     {
         $objects = $this->convertObjectsToArray($objects);
 
-        $objects = $this->wrap($objects);
-
         foreach ($objects as $attributes) {
             $object = $this->importAttributes($attributes);
-
             $this->importRelations($object, $attributes);
         }
     }
@@ -51,7 +48,7 @@ protected function convertObjectsToArray($objects): array
             $objects = $objects->toArray();
         }
 
-        return (array) $objects;
+        return $this->wrap((array) $objects);
     }
 
     protected function wrap(array $objects): array
@@ -71,7 +68,10 @@ protected function importRelations($object, $attributes)
         $relationsNames = array_intersect(array_keys($attributes), $this->importable->getJsonImportableRelations());
 
         foreach ($relationsNames as $relationName) {
-            $this->importChildrenIfImportable($this->getRelationObject($object, $relationName), $this->wrap($attributes[$relationName]));
+            $children = $this->convertObjectsToArray($attributes[$relationName]);
+            $relation = $this->getRelationObject($object, $relationName);
+
+            $this->importChildrenIfImportable($relation, $children);
         }
     }
 
diff --git a/tests/JsonImporterTest.php b/tests/JsonImporterTest.php
index ca156cd..85f50d1 100644
--- a/tests/JsonImporterTest.php
+++ b/tests/JsonImporterTest.php
@@ -22,12 +22,40 @@ protected function assertAllImportedInDatabase()
         $this->assertFooIsImported();
         $this->assertBarsAreImported();
         $this->assertBazsAreImported();
-        $this->assertEquals(0, DoNotExport::query()->count());
+        $this->assertEquals(0, DoNotExport::count());
+    }
+
+    protected function assertFooIsImported()
+    {
+        $this->assertEquals(1, Foo::count());
+        $this->assertEquals(
+            ['id' => 1, 'author' => 'Mathieu TUDISCO', 'username' => '@mathieutu'],
+            Foo::first()->toArray()
+        );
+    }
+
+    protected function assertBarsAreImported()
+    {
+        $this->assertEquals(2, Bar::count());
+        $bars = Foo::first()->bars;
+        $this->assertEquals([
+            ['id' => 1, 'name' => 'bar1', 'foo_id' => 1],
+            ['id' => 2, 'name' => 'bar2', 'foo_id' => 1],
+        ], $bars->toArray());
+    }
+
+    protected function assertBazsAreImported()
+    {
+        $this->assertEquals(2, Baz::count());
+        foreach (Foo::with('bars.baz')->first()->bars as $bar) {
+            $baz = $bar->baz;
+            $this->assertEquals(['id' => $baz->id, 'name' => $bar->name . '_baz', 'bar_id' => $bar->id], $baz->toArray());
+        }
     }
 
     public function testImportWithoutRelation()
     {
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
 
         unset($import['bars'][1]['baz']);
 
@@ -36,14 +64,19 @@ public function testImportWithoutRelation()
         $this->assertFooIsImported();
         $this->assertBarsAreImported();
 
-        $this->assertEquals(1, Baz::query()->count());
+        $this->assertEquals(1, Baz::count());
         $baz = Foo::with('bars.baz')->first()->bars->pluck('baz');
         $this->assertEquals([['id' => 1, 'name' => 'bar1_baz', 'bar_id' => '1'], null], $baz->toArray());
     }
 
+    private function getImportArray(): array
+    {
+        return json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+    }
+
     public function testImportWithAnEmptyRelation()
     {
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
 
         $import['bars'] = [];
 
@@ -51,28 +84,28 @@ public function testImportWithAnEmptyRelation()
 
         Foo::importFromJson($import);
 
-        $this->assertEquals(1, Foo::query()->count());
-        $this->assertEquals(0, Bar::query()->count());
-        $this->assertEquals(0, Baz::query()->count());
-        $this->assertEquals(0, DoNotExport::query()->count());
+        $this->assertEquals(1, Foo::count());
+        $this->assertEquals(0, Bar::count());
+        $this->assertEquals(0, Baz::count());
+        $this->assertEquals(0, DoNotExport::count());
     }
 
     public function testImportSeveralTimesWillJustAdd()
     {
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
 
         Foo::importFromJson($import);
 
-        $fooCount = Foo::query()->count();
-        $barCount = Bar::query()->count();
-        $bazCount = Baz::query()->count();
-        $doNotExportCount = DoNotExport::query()->count();
+        $fooCount = Foo::count();
+        $barCount = Bar::count();
+        $bazCount = Baz::count();
+        $doNotExportCount = DoNotExport::count();
 
         foreach (range(1, 3) as $time) {
-            $this->assertEquals($time * $fooCount, Foo::query()->count());
-            $this->assertEquals($time * $barCount, Bar::query()->count());
-            $this->assertEquals($time * $bazCount, Baz::query()->count());
-            $this->assertEquals($time * $doNotExportCount, DoNotExport::query()->count());
+            $this->assertEquals($time * $fooCount, Foo::count());
+            $this->assertEquals($time * $barCount, Bar::count());
+            $this->assertEquals($time * $bazCount, Baz::count());
+            $this->assertEquals($time * $doNotExportCount, DoNotExport::count());
 
             Foo::importFromJson($import);
         }
@@ -80,11 +113,43 @@ public function testImportSeveralTimesWillJustAdd()
 
     public function testImportFromArray()
     {
-        Foo::importFromJson(json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true));
+        Foo::importFromJson($this->getImportArray());
 
         $this->assertAllImportedInDatabase();
     }
 
+    public function testImportNullRelation()
+    {
+        $objects = $this->getImportArray();
+        $objects['bars'] = null;
+
+        Foo::importFromJson($objects);
+
+        $this->assertFooIsImported();
+
+        $this->assertEquals(0, Bar::count());
+        $bars = Foo::first()->bars;
+        $this->assertEquals([], $bars->toArray());
+
+        $this->assertEquals(0, Baz::count());
+        $this->assertEquals(0, DoNotExport::count());
+    }
+
+    public function testImportNullAttribute()
+    {
+        $objects = $this->getImportArray();
+        $objects['author'] = null;
+
+        Foo::importFromJson($objects);
+
+        $this->assertEquals(1, Foo::count());
+        $this->assertEquals(['id' => 1, 'author' => null, 'username' => '@mathieutu'], Foo::first()->toArray());
+
+        $this->assertBarsAreImported();
+        $this->assertBazsAreImported();
+        $this->assertEquals(0, DoNotExport::count());
+    }
+
     public function testImportBadJson()
     {
         $this->expectException(JsonDecodingException::class);
@@ -94,7 +159,7 @@ public function testImportBadJson()
 
     public function testImportUnWantedData()
     {
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
         $import['bad'] = 'attribute';
 
         Foo::importFromJson($import);
@@ -104,7 +169,7 @@ public function testImportUnWantedData()
 
     public function testImportNonRelationMethodWithDefaultRelations()
     {
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
         $import['otherMethod'] = ['Hello you!'];
 
         Foo::importFromJson($import);
@@ -117,7 +182,7 @@ public function testImportANonRelationMethodWithCustomRelations()
         $this->expectException(UnknownAttributeException::class);
         $this->expectExceptionMessage('Unknown attribute or HasOneorMany relation "otherMethod" in "MathieuTu\\JsonSyncer\\Tests\\Stubs\\Foo".');
 
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
         $import['otherMethod'] = [];
 
         (new Foo)->setJsonImportableRelationsForTests(['bars', 'otherMethod'])
@@ -129,7 +194,7 @@ public function testImportUnknownRelationWithCustomRelations()
         $this->expectException(UnknownAttributeException::class);
         $this->expectExceptionMessage('Unknown attribute or HasOneorMany relation "test" in "MathieuTu\\JsonSyncer\\Tests\\Stubs\\Foo".');
 
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
         $import['test'] = [];
 
         (new Foo)->setJsonImportableRelationsForTests(['bars', 'test'])
@@ -138,7 +203,7 @@ public function testImportUnknownRelationWithCustomRelations()
 
     public function testImportWithCustomRelationsAndAttributes()
     {
-        $import = json_decode(file_get_contents(__DIR__ . '/Stubs/import.json'), true);
+        $import = $this->getImportArray();
 
         (new Foo)->setJsonImportableRelationsForTests(['bars'])
             ->setJsonImportableAttributesForTests(['author'])
@@ -155,7 +220,8 @@ public function testIsImportingMethod()
             'author' => 'Mathieu',
         ];
 
-        $foo = new class extends Foo {
+        $foo = new class extends Foo
+        {
             protected $fillable = ['author'];
             protected $table = 'foos';
 
@@ -188,32 +254,7 @@ public function testImportNonImportableObjects()
         ];
 
         Baz::importFromJson($baz);
-        $this->assertEquals(1, Baz::query()->count());
-        $this->assertEquals(0, DoNotExport::query()->count());
-    }
-
-    protected function assertBazsAreImported()
-    {
-        $this->assertEquals(2, Baz::query()->count());
-        foreach (Foo::with('bars.baz')->first()->bars as $bar) {
-            $baz = $bar->baz;
-            $this->assertEquals(['id' => $baz->id, 'name' => $bar->name . '_baz', 'bar_id' => $bar->id], $baz->toArray());
-        }
-    }
-
-    protected function assertBarsAreImported()
-    {
-        $this->assertEquals(2, Bar::query()->count());
-        $bars = Foo::query()->first()->bars;
-        $this->assertEquals([
-            ['id' => 1, 'name' => 'bar1', 'foo_id' => 1],
-            ['id' => 2, 'name' => 'bar2', 'foo_id' => 1],
-        ], $bars->toArray());
-    }
-
-    protected function assertFooIsImported()
-    {
-        $this->assertEquals(1, Foo::query()->count());
-        $this->assertEquals(['id' => 1, 'author' => 'Mathieu TUDISCO', 'username' => '@mathieutu'], Foo::query()->first()->toArray());
+        $this->assertEquals(1, Baz::count());
+        $this->assertEquals(0, DoNotExport::count());
     }
 }