diff --git a/manimlib/scene/scene_file_writer.py b/manimlib/scene/scene_file_writer.py
index ef1586e1..80b11108 100644
--- a/manimlib/scene/scene_file_writer.py
+++ b/manimlib/scene/scene_file_writer.py
@@ -286,7 +286,7 @@ class SceneFileWriter(object):
             for pf_path in partial_movie_files:
                 if os.name == 'nt':
                     pf_path = pf_path.replace('\\', '/')
-                fp.write("file \'{}\'\n".format(pf_path))
+                fp.write("file \'file:{}\'\n".format(pf_path))
 
         movie_file_path = self.get_movie_file_path()
         commands = [