diff --git a/dlls/winegstreamer/media_source.c b/dlls/winegstreamer/media_source.c
index 05544ef7abe..01ab626254a 100644
--- a/dlls/winegstreamer/media_source.c
+++ b/dlls/winegstreamer/media_source.c
@@ -1315,8 +1315,6 @@ static HRESULT media_source_constructor(IMFByteStream *bytestream, struct media_
     if (FAILED(hr = MFAllocateWorkQueue(&object->async_commands_queue)))
         goto fail;
 
-    object->read_thread = CreateThread(NULL, 0, read_thread, object, 0, NULL);
-
     if (!(parser = unix_funcs->wg_decodebin_parser_create()))
     {
         hr = E_OUTOFMEMORY;
@@ -1324,6 +1322,8 @@ static HRESULT media_source_constructor(IMFByteStream *bytestream, struct media_
     }
     object->wg_parser = parser;
 
+    object->read_thread = CreateThread(NULL, 0, read_thread, object, 0, NULL);
+
     object->state = SOURCE_OPENING;
 
     if (FAILED(hr = unix_funcs->wg_parser_connect(parser, file_size)))