--- a/dom/system/IOUtils.cpp
+++ b/dom/system/IOUtils.cpp
@@ -208,17 +208,16 @@ already_AddRefed<Promise> IOUtils::Read(
     toRead.emplace(aOptions.mMaxBytes.Value());
   }
 
   RunOnBackgroundThread<nsTArray<uint8_t>>(
       promise,
       [file = std::move(file), toRead, decompress = aOptions.mDecompress]() {
         return ReadSync(file, toRead, decompress);
       });
-
   return promise.forget();
 }
 
 /* static */
 already_AddRefed<Promise> IOUtils::ReadUTF8(GlobalObject& aGlobal,
                                             const nsAString& aPath,
                                             const ReadUTF8Options& aOptions) {
   MOZ_DIAGNOSTIC_ASSERT(XRE_IsParentProcess());
@@ -558,18 +557,17 @@ already_AddRefed<Promise> IOUtils::Creat
   if (er.Failed()) {
     return nullptr;
   }
   MOZ_ASSERT(promise);
   return do_AddRef(promise);
 }
 
 /* static */
-void IOUtils::RejectJSPromise(const RefPtr<Promise>& aPromise,
-                              const IOError& aError) {
+void IOUtils::RejectJSPromise(Promise* aPromise, const IOError& aError) {
   const auto& errMsg = aError.Message();
 
   switch (aError.Code()) {
     case NS_ERROR_FILE_TARGET_DOES_NOT_EXIST:
     case NS_ERROR_FILE_NOT_FOUND:
       aPromise->MaybeRejectWithNotFoundError(errMsg.refOr("File not found"_ns));
       break;
     case NS_ERROR_FILE_ACCESS_DENIED:

--- a/dom/system/IOUtils.h
+++ b/dom/system/IOUtils.h
@@ -138,18 +138,17 @@ class IOUtils final {
   // Allow conversion of |InternalFileInfo| with |ToJSValue|.
   friend MOZ_MUST_USE bool ToJSValue(JSContext* aCx,
                                      const InternalFileInfo& aInternalFileInfo,
                                      JS::MutableHandle<JS::Value> aValue);
 
   /**
    * Rejects |aPromise| with an appropriate |DOMException| describing |aError|.
    */
-  static void RejectJSPromise(const RefPtr<Promise>& aPromise,
-                              const IOError& aError);
+  static void RejectJSPromise(Promise* aPromise, const IOError& aError);
 
   /**
    * Attempts to read the entire file at |aPath| into a buffer.
    *
    * @param aFile       The location of the file.
    * @param aMaxBytes   If |Some|, then only read up this this number of bytes,
    *                    otherwise attempt to read the whole file.
    * @param aDecompress If true, decompress the bytes read from disk before