diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 58b34e087..d1953c18f 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -1527,6 +1527,7 @@ class YoutubeDL(object):
             pps_chain.extend(ie_info['__postprocessors'])
         pps_chain.extend(self._pps)
         for pp in pps_chain:
+            files_to_delete = []
             try:
                 files_to_delete, info = pp.run(info)
             except PostProcessingError as e: