diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 50228bb321..3cabfbc032 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -1288,6 +1288,9 @@ def process_video_result(self, info_dict, download=True):
 
             if format.get('format_id') is None:
                 format['format_id'] = compat_str(i)
+            else:
+                # Sanitize format_id from characters used in format selector expression
+                format['format_id'] = re.sub('[\s,/+\[\]()]', '_', format['format_id'])
             format_id = format['format_id']
             if format_id not in formats_dict:
                 formats_dict[format_id] = []