diff --git a/src/Abstractor/Eloquent/Model.php b/src/Abstractor/Eloquent/Model.php
index 85c1db1..e8f12c0 100644
--- a/src/Abstractor/Eloquent/Model.php
+++ b/src/Abstractor/Eloquent/Model.php
@@ -397,6 +397,7 @@ public function persist(Request $request)
 
 
         $fields = $this->getEditFields(true);
+        $foreignFields = array_diff_key($fields['main'], $this->getEditFields(false)['main']);
         if (empty($fields['main']) && $this->getRelations()->isEmpty()) {
             return;
         }
@@ -412,6 +413,10 @@ public function persist(Request $request)
                 $fieldName = $field->getName();
                 $requestValue = $request->input("main.{$fieldName}");
 
+                if (! empty($foreignFields) && (! empty($foreignFields[$fieldName])) && (empty($requestValue))) {
+                    $requestValue = null;
+                }
+
                 if (get_class($field->getFormField()) === \FormManager\Fields\Checkbox::class) {
                     if (empty($requestValue)) {
                         // Unchecked checkboxes are not sent, so we force setting them to false
@@ -439,7 +444,10 @@ public function persist(Request $request)
                     continue;
                 }
 
-                if (! empty($requestValue) || (empty($requestValue) && ! empty($item->getAttribute($fieldName)))) {
+                if (! empty($requestValue)
+                    || (empty($requestValue) && !empty($item->getAttribute($fieldName)))
+                    || (! empty($foreignFields) && (! empty($foreignFields[$fieldName])) && (empty($requestValue)))
+                ) {
                     $item->setAttribute(
                         $fieldName,
                         $field->applyFunctions($requestValue)
diff --git a/tests/Abstractor/Eloquent/ModelTest.php b/tests/Abstractor/Eloquent/ModelTest.php
index 02b8b16..b78c348 100644
--- a/tests/Abstractor/Eloquent/ModelTest.php
+++ b/tests/Abstractor/Eloquent/ModelTest.php
@@ -498,6 +498,14 @@ public function test_persist()
                 $fieldMock,
             ]
         ]);
+        $this->sut->shouldReceive('getEditFields')->times(1)->with(false)->andReturn([
+            'main' => [
+                $fieldMock,
+                $fieldMock,
+                $fieldMock,
+                $fieldMock,
+            ]
+        ]);
 
         $this->sut->shouldReceive('getRelations')->andReturn(collect(['group' => $relationMock = $this->mock('\Anavel\Crud\Abstractor\Eloquent\Relation\Relation')]));