diff --git a/src/app/Library/CrudPanel/CrudField.php b/src/app/Library/CrudPanel/CrudField.php
index f9f807099a..76bc301a89 100644
--- a/src/app/Library/CrudPanel/CrudField.php
+++ b/src/app/Library/CrudPanel/CrudField.php
@@ -202,7 +202,7 @@ public function makeLast()
      */
     public function size($numberOfColumns)
     {
-        $this->attributes['wrapper']['class'] = 'form-group col-md-'.$numberOfColumns;
+        $this->attributes['wrapper']['class'] = 'form-group col-md-'.$numberOfColumns.' mb-3';
 
         return $this->save();
     }
diff --git a/tests/Unit/CrudPanel/CrudPanelFieldsTest.php b/tests/Unit/CrudPanel/CrudPanelFieldsTest.php
index 37ca4fd689..973bcaab59 100644
--- a/tests/Unit/CrudPanel/CrudPanelFieldsTest.php
+++ b/tests/Unit/CrudPanel/CrudPanelFieldsTest.php
@@ -777,7 +777,7 @@ public function testItCanAddAFluentField()
             ],
             'store_in' => 'some',
             'wrapper' => [
-                'class' => 'form-group col-md-6',
+                'class' => 'form-group col-md-6 mb-3',
             ],
             'events' => [
                 'created' => function () {