diff --git a/app/Models/AppVersion.php b/app/Models/AppVersion.php
index 149abee..cbcbfd0 100644
--- a/app/Models/AppVersion.php
+++ b/app/Models/AppVersion.php
@@ -69,6 +69,30 @@ class AppVersion extends Model
             ->value('apk_url');
     }
 
+    protected function apkUrl(): Attribute
+    {
+        return Attribute::make(
+            set: function (mixed $value) {
+                if ((string) $value === '') {
+                    $value = null;
+                }
+                return $value;
+            },
+        );
+    }
+
+    protected function wgtUrl(): Attribute
+    {
+        return Attribute::make(
+            set: function (mixed $value) {
+                if ((string) $value === '') {
+                    $value = null;
+                }
+                return $value;
+            },
+        );
+    }
+
     protected function isRelease(): Attribute
     {
         return Attribute::make(