diff --git a/youtube_dl/extractor/firedrive.py b/youtube_dl/extractor/firedrive.py
index d26145db1..6d73c8a4a 100644
--- a/youtube_dl/extractor/firedrive.py
+++ b/youtube_dl/extractor/firedrive.py
@@ -8,7 +8,6 @@ from ..utils import (
     ExtractorError,
     compat_urllib_parse,
     compat_urllib_request,
-    determine_ext,
 )
 
 
diff --git a/youtube_dl/extractor/tenplay.py b/youtube_dl/extractor/tenplay.py
index 8477840fc..81ba169fb 100644
--- a/youtube_dl/extractor/tenplay.py
+++ b/youtube_dl/extractor/tenplay.py
@@ -1,8 +1,6 @@
 # coding: utf-8
 from __future__ import unicode_literals
 
-import re
-
 from .common import InfoExtractor
 
 
diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 071aa7519..072e711c2 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -1,15 +1,12 @@
 # coding: utf-8
 
-import collections
 import errno
 import io
 import itertools
 import json
 import os.path
 import re
-import struct
 import traceback
-import zlib
 
 from .common import InfoExtractor, SearchInfoExtractor
 from .subtitles import SubtitlesInfoExtractor