diff --git a/src/boxerror.js b/src/boxerror.js
index 530c8cd06..96e13cbab 100644
--- a/src/boxerror.js
+++ b/src/boxerror.js
@@ -74,7 +74,11 @@ BoxError.TIMEOUT = 'Timeout';
 BoxError.TRY_AGAIN = 'Try Again';
 
 BoxError.prototype.toPlainObject = function () {
-    return Object.assign({}, { message: this.message, reason: this.reason }, this.details);
+    return {
+        message: this.message,
+        reason: this.reason,
+        details: this.details
+    };
 };
 
 // this is a class method for now in case error is not a BoxError