diff --git a/youtube_dl/InfoExtractors.py b/youtube_dl/InfoExtractors.py
index a94648dcf..c696bb968 100755
--- a/youtube_dl/InfoExtractors.py
+++ b/youtube_dl/InfoExtractors.py
@@ -308,7 +308,7 @@ class YoutubeIE(InfoExtractor):
                 else:
                     raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
             except (IOError, netrc.NetrcParseError) as err:
-                self._downloader.to_stderr(u'WARNING: parsing .netrc: %s' % compat_str(err))
+                self._downloader.report_warning(u'parsing .netrc: %s' % compat_str(err))
                 return
 
         # Set language
@@ -317,7 +317,7 @@ class YoutubeIE(InfoExtractor):
             self.report_lang()
             compat_urllib_request.urlopen(request).read()
         except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.to_stderr(u'WARNING: unable to set language: %s' % compat_str(err))
+            self._downloader.report_warning(u'unable to set language: %s' % compat_str(err))
             return
 
         # No authentication to be performed
@@ -328,7 +328,7 @@ class YoutubeIE(InfoExtractor):
         try:
             login_page = compat_urllib_request.urlopen(request).read().decode('utf-8')
         except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.to_stderr(u'WARNING: unable to fetch login page: %s' % compat_str(err))
+            self._downloader.report_warning(u'unable to fetch login page: %s' % compat_str(err))
             return
 
         galx = None
@@ -372,10 +372,10 @@ class YoutubeIE(InfoExtractor):
             self.report_login()
             login_results = compat_urllib_request.urlopen(request).read().decode('utf-8')
             if re.search(r'(?i)<form[^>]* id="gaia_loginform"', login_results) is not None:
-                self._downloader.to_stderr(u'WARNING: unable to log in: bad username or password')
+                self._downloader.report_warning(u'unable to log in: bad username or password')
                 return
         except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.to_stderr(u'WARNING: unable to log in: %s' % compat_str(err))
+            self._downloader.report_warning(u'unable to log in: %s' % compat_str(err))
             return
 
         # Confirm age
@@ -1456,7 +1456,7 @@ class YoutubeSearchIE(InfoExtractor):
                     self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
                     return
                 elif n > self._max_youtube_results:
-                    self._downloader.to_stderr(u'WARNING: ytsearch returns max %i results (you requested %i)' % (self._max_youtube_results, n))
+                    self._downloader.report_warning(u'ytsearch returns max %i results (you requested %i)' % (self._max_youtube_results, n))
                     n = self._max_youtube_results
                 self._download_n_results(query, n)
                 return
@@ -1538,7 +1538,7 @@ class GoogleSearchIE(InfoExtractor):
                     self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
                     return
                 elif n > self._max_google_results:
-                    self._downloader.to_stderr(u'WARNING: gvsearch returns max %i results (you requested %i)' % (self._max_google_results, n))
+                    self._downloader.report_warning(u'gvsearch returns max %i results (you requested %i)' % (self._max_google_results, n))
                     n = self._max_google_results
                 self._download_n_results(query, n)
                 return
@@ -1622,7 +1622,7 @@ class YahooSearchIE(InfoExtractor):
                     self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
                     return
                 elif n > self._max_yahoo_results:
-                    self._downloader.to_stderr(u'WARNING: yvsearch returns max %i results (you requested %i)' % (self._max_yahoo_results, n))
+                    self._downloader.report_warning(u'yvsearch returns max %i results (you requested %i)' % (self._max_yahoo_results, n))
                     n = self._max_yahoo_results
                 self._download_n_results(query, n)
                 return
@@ -2080,7 +2080,7 @@ class FacebookIE(InfoExtractor):
                 else:
                     raise netrc.NetrcParseError('No authenticators for %s' % self._NETRC_MACHINE)
             except (IOError, netrc.NetrcParseError) as err:
-                self._downloader.to_stderr(u'WARNING: parsing .netrc: %s' % compat_str(err))
+                self._downloader.report_warning(u'parsing .netrc: %s' % compat_str(err))
                 return
 
         if useremail is None:
@@ -2097,10 +2097,10 @@ class FacebookIE(InfoExtractor):
             self.report_login()
             login_results = compat_urllib_request.urlopen(request).read()
             if re.search(r'<form(.*)name="login"(.*)</form>', login_results) is not None:
-                self._downloader.to_stderr(u'WARNING: unable to log in: bad username/password, or exceded login rate limit (~3/min). Check credentials or wait.')
+                self._downloader.report_warning(u'unable to log in: bad username/password, or exceded login rate limit (~3/min). Check credentials or wait.')
                 return
         except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
-            self._downloader.to_stderr(u'WARNING: unable to log in: %s' % compat_str(err))
+            self._downloader.report_warning(u'unable to log in: %s' % compat_str(err))
             return
 
     def _real_extract(self, url):
@@ -3767,7 +3767,7 @@ class YouPornIE(InfoExtractor):
         # Get the video date
         result = re.search(r'Date:</label>(?P<date>.*) </li>', webpage)
         if result is None:
-            self._downloader.to_stderr(u'WARNING: unable to extract video date')
+            self._downloader.report_warning(u'unable to extract video date')
             upload_date = None
         else:
             upload_date = result.group('date').strip()
@@ -3775,7 +3775,7 @@ class YouPornIE(InfoExtractor):
         # Get the video uploader
         result = re.search(r'Submitted:</label>(?P<uploader>.*)</li>', webpage)
         if result is None:
-            self._downloader.to_stderr(u'WARNING: unable to extract uploader')
+            self._downloader.report_warning(u'unable to extract uploader')
             video_uploader = None
         else:
             video_uploader = result.group('uploader').strip()