diff --git a/core/file_transfer.js b/core/file_transfer.js
index 83dedc13..5f0138e2 100644
--- a/core/file_transfer.js
+++ b/core/file_transfer.js
@@ -205,7 +205,7 @@ exports.getModule = class TransferFileModule extends MenuModule {
         let tryDstPath;
 
         async.until(
-            () => movedOk,  //  until moved OK
+            (callback) => callback(null, movedOk),  //  until moved OK
             (cb) => {
                 if(0 === renameIndex) {
                     //  try originally supplied path first
diff --git a/core/file_util.js b/core/file_util.js
index fdea4e45..56d8d5ac 100644
--- a/core/file_util.js
+++ b/core/file_util.js
@@ -38,7 +38,7 @@ function moveOrCopyFileWithCollisionHandling(src, dst, operation, cb) {
     }
 
     async.until(
-        () => opOk, //  until moved OK
+        (callback) => callback(null, opOk), //  until moved OK
         (cb) => {
             if(0 === renameIndex) {
                 //  try originally supplied path first