diff --git a/youtube_dl/extractor/rtbf.py b/youtube_dl/extractor/rtbf.py
index acff9766ac..3b0f3080b1 100644
--- a/youtube_dl/extractor/rtbf.py
+++ b/youtube_dl/extractor/rtbf.py
@@ -99,7 +99,7 @@ def _real_extract(self, url):
         http_url = data.get('url')
         if formats and http_url and re.search(height_re, http_url):
             http_url = fix_url(http_url)
-            for m3u8_f in formats.copy():
+            for m3u8_f in formats[:]:
                 height = m3u8_f.get('height')
                 if not height:
                     continue