diff --git a/youtube_dl/compat.py b/youtube_dl/compat.py
index e48c761a69..1392361a16 100644
--- a/youtube_dl/compat.py
+++ b/youtube_dl/compat.py
@@ -341,9 +341,9 @@ def compat_parse_qs(qs, keep_blank_values=False, strict_parsing=False,
         return parsed_result
 
 try:
-    from shlex import quote as shlex_quote
+    from shlex import quote as compat_shlex_quote
 except ImportError:  # Python < 3.3
-    def shlex_quote(s):
+    def compat_shlex_quote(s):
         if re.match(r'^[-_\w./]+$', s):
             return s
         else:
@@ -466,18 +466,6 @@ def compat_print(s):
         print(s)
 
 
-try:
-    subprocess_check_output = subprocess.check_output
-except AttributeError:
-    def subprocess_check_output(*args, **kwargs):
-        assert 'input' not in kwargs
-        p = subprocess.Popen(*args, stdout=subprocess.PIPE, **kwargs)
-        output, _ = p.communicate()
-        ret = p.poll()
-        if ret:
-            raise subprocess.CalledProcessError(ret, p.args, output=output)
-        return output
-
 if sys.version_info < (3, 0) and sys.platform == 'win32':
     def compat_getpass(prompt, *args, **kwargs):
         if isinstance(prompt, compat_str):
@@ -635,6 +623,7 @@ def compat_struct_unpack(spec, *args):
     'compat_parse_qs',
     'compat_print',
     'compat_setenv',
+    'compat_shlex_quote',
     'compat_shlex_split',
     'compat_socket_create_connection',
     'compat_str',
@@ -656,7 +645,5 @@ def compat_struct_unpack(spec, *args):
     'compat_urlretrieve',
     'compat_xml_parse_error',
     'compat_xpath',
-    'shlex_quote',
-    'subprocess_check_output',
     'workaround_optparse_bug9161',
 ]
diff --git a/youtube_dl/postprocessor/execafterdownload.py b/youtube_dl/postprocessor/execafterdownload.py
index 74f66d669c..90630c2d73 100644
--- a/youtube_dl/postprocessor/execafterdownload.py
+++ b/youtube_dl/postprocessor/execafterdownload.py
@@ -3,7 +3,7 @@
 import subprocess
 
 from .common import PostProcessor
-from ..compat import shlex_quote
+from ..compat import compat_shlex_quote
 from ..utils import PostProcessingError
 
 
@@ -17,7 +17,7 @@ def run(self, information):
         if '{}' not in cmd:
             cmd += ' {}'
 
-        cmd = cmd.replace('{}', shlex_quote(information['filepath']))
+        cmd = cmd.replace('{}', compat_shlex_quote(information['filepath']))
 
         self._downloader.to_screen('[exec] Executing command: %s' % cmd)
         retCode = subprocess.call(cmd, shell=True)
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index dbac38b555..e8b09e9db9 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -42,6 +42,7 @@
     compat_http_client,
     compat_kwargs,
     compat_parse_qs,
+    compat_shlex_quote,
     compat_socket_create_connection,
     compat_str,
     compat_struct_pack,
@@ -52,7 +53,6 @@
     compat_urllib_request,
     compat_urlparse,
     compat_xpath,
-    shlex_quote,
 )
 
 from .socks import (
@@ -1977,7 +1977,7 @@ def ytdl_is_updateable():
 
 def args_to_str(args):
     # Get a short string representation for a subprocess command
-    return ' '.join(shlex_quote(a) for a in args)
+    return ' '.join(compat_shlex_quote(a) for a in args)
 
 
 def error_to_compat_str(err):