diff --git a/app/Models/Device.php b/app/Models/Device.php
index 38ca180499..f197ce620f 100644
--- a/app/Models/Device.php
+++ b/app/Models/Device.php
@@ -401,8 +401,11 @@ class Device extends BaseModel
         });
 
         if ($attrib_index !== false) {
+            $deleted=(bool)$this->attribs->get($attrib_index)->delete();
+            // only forget the attrib_index after delete, otherwise delete() will fail fatally with:
+            // Symfony\\Component\\Debug\Exception\\FatalThrowableError(code: 0):  Call to a member function delete() on null
             $this->attribs->forget($attrib_index);
-            return (bool)$this->attribs->get($attrib_index)->delete();
+            return $deleted;
         }
 
         return false;