diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index e53a2b8ad..de2b133e0 100644
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -142,14 +142,10 @@ class YoutubeDL(object):
 
     def to_screen(self, message, skip_eol=False):
         """Print message to stdout if not in quiet mode."""
-        assert type(message) == type(u'')
         if not self.params.get('quiet', False):
             terminator = [u'\n', u''][skip_eol]
             output = message + terminator
-            if 'b' in getattr(self._screen_file, 'mode', '') or sys.version_info[0] < 3: # Python 2 lies about the mode of sys.stdout/sys.stderr
-                output = output.encode(preferredencoding(), 'ignore')
-            self._screen_file.write(output)
-            self._screen_file.flush()
+            write_string(output, self._screen_file)
 
     def to_stderr(self, message):
         """Print message to stderr."""
diff --git a/youtube_dl/__init__.py b/youtube_dl/__init__.py
index 0022a4e7a..9efd7c3f7 100644
--- a/youtube_dl/__init__.py
+++ b/youtube_dl/__init__.py
@@ -354,7 +354,7 @@ def parseOpts(overrideArguments=None):
     if overrideArguments is not None:
         opts, args = parser.parse_args(overrideArguments)
         if opts.verbose:
-            sys.stderr.write(u'[debug] Override config: ' + repr(overrideArguments) + '\n')
+            write_string(u'[debug] Override config: ' + repr(overrideArguments) + '\n')
     else:
         xdg_config_home = os.environ.get('XDG_CONFIG_HOME')
         if xdg_config_home:
@@ -367,9 +367,9 @@ def parseOpts(overrideArguments=None):
         argv = systemConf + userConf + commandLineConf
         opts, args = parser.parse_args(argv)
         if opts.verbose:
-            sys.stderr.write(u'[debug] System config: ' + repr(_hide_login_info(systemConf)) + '\n')
-            sys.stderr.write(u'[debug] User config: ' + repr(_hide_login_info(userConf)) + '\n')
-            sys.stderr.write(u'[debug] Command-line args: ' + repr(_hide_login_info(commandLineConf)) + '\n')
+            write_string(u'[debug] System config: ' + repr(_hide_login_info(systemConf)) + '\n')
+            write_string(u'[debug] User config: ' + repr(_hide_login_info(userConf)) + '\n')
+            write_string(u'[debug] Command-line args: ' + repr(_hide_login_info(commandLineConf)) + '\n')
 
     return parser, opts, args
 
@@ -392,7 +392,7 @@ def _real_main(argv=None):
         except (IOError, OSError) as err:
             if opts.verbose:
                 traceback.print_exc()
-            sys.stderr.write(u'ERROR: unable to open cookie file\n')
+            write_string(u'ERROR: unable to open cookie file\n')
             sys.exit(101)
     # Set user agent
     if opts.user_agent is not None:
@@ -419,7 +419,7 @@ def _real_main(argv=None):
             batchurls = [x.strip() for x in batchurls]
             batchurls = [x for x in batchurls if len(x) > 0 and not re.search(r'^[#/;]', x)]
             if opts.verbose:
-                sys.stderr.write(u'[debug] Batch file urls: ' + repr(batchurls) + u'\n')
+                write_string(u'[debug] Batch file urls: ' + repr(batchurls) + u'\n')
         except IOError:
             sys.exit(u'ERROR: batch file could not be read')
     all_urls = batchurls + args
@@ -611,7 +611,7 @@ def _real_main(argv=None):
         })
 
     if opts.verbose:
-        sys.stderr.write(u'[debug] youtube-dl version ' + __version__ + u'\n')
+        write_string(u'[debug] youtube-dl version ' + __version__ + u'\n')
         try:
             sp = subprocess.Popen(
                 ['git', 'rev-parse', '--short', 'HEAD'],
@@ -620,14 +620,14 @@ def _real_main(argv=None):
             out, err = sp.communicate()
             out = out.decode().strip()
             if re.match('[0-9a-f]+', out):
-                sys.stderr.write(u'[debug] Git HEAD: ' + out + u'\n')
+                write_string(u'[debug] Git HEAD: ' + out + u'\n')
         except:
             try:
                 sys.exc_clear()
             except:
                 pass
-        sys.stderr.write(u'[debug] Python version %s - %s' %(platform.python_version(), platform_name()) + u'\n')
-        sys.stderr.write(u'[debug] Proxy map: ' + str(proxy_handler.proxies) + u'\n')
+        write_string(u'[debug] Python version %s - %s' %(platform.python_version(), platform_name()) + u'\n')
+        write_string(u'[debug] Proxy map: ' + str(proxy_handler.proxies) + u'\n')
 
     ydl.add_default_info_extractors()
 
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py
index 5558d4737..814a9b6be 100644
--- a/youtube_dl/utils.py
+++ b/youtube_dl/utils.py
@@ -790,6 +790,18 @@ def platform_name():
     return res
 
 
+def write_string(s, out=None):
+    if out is None:
+        out = sys.stderr
+    assert type(s) == type(u'')
+
+    if ('b' in getattr(out, 'mode', '') or
+            sys.version_info[0] < 3):  # Python 2 lies about mode of sys.stderr
+        s = s.encode(preferredencoding(), 'ignore')
+    out.write(s)
+    out.flush()
+
+
 def bytes_to_intlist(bs):
     if not bs:
         return []