diff --git a/README.md b/README.md
index 1aab0ba945..ce5af129ea 100644
--- a/README.md
+++ b/README.md
@@ -737,9 +737,6 @@ ## Workarounds:
     --prefer-insecure                Use an unencrypted connection to retrieve
                                      information about the video (Currently
                                      supported only for YouTube)
-    --user-agent UA                  Specify a custom user agent
-    --referer URL                    Specify a custom referer, use if the video
-                                     access is restricted to one domain
     --add-header FIELD:VALUE         Specify a custom HTTP header and its value,
                                      separated by a colon ":". You can use this
                                      option multiple times
@@ -1866,6 +1863,8 @@ #### Redundant options
     --reject-title REGEX             --match-filter "title !~= (?i)REGEX"
     --min-views COUNT                --match-filter "view_count >=? COUNT"
     --max-views COUNT                --match-filter "view_count <=? COUNT"
+    --user-agent UA                  --add-header "User-Agent:UA"
+    --referer URL                    --add-header "Referer:URL"
 
 
 #### Not recommended
diff --git a/yt_dlp/YoutubeDL.py b/yt_dlp/YoutubeDL.py
index 0aee3b1224..49143cb169 100644
--- a/yt_dlp/YoutubeDL.py
+++ b/yt_dlp/YoutubeDL.py
@@ -83,6 +83,7 @@
     make_dir,
     make_HTTPS_handler,
     MaxDownloadsReached,
+    merge_headers,
     network_exceptions,
     number_of_digits,
     orderedSet,
@@ -332,6 +333,7 @@ class YoutubeDL(object):
     nocheckcertificate:  Do not verify SSL certificates
     prefer_insecure:   Use HTTP instead of HTTPS to retrieve information.
                        At the moment, this is only supported by YouTube.
+    http_headers:      A dictionary of custom headers to be used for all requests
     proxy:             URL of the proxy server to use
     geo_verification_proxy:  URL of the proxy to use for IP address verification
                        on geo-restricted sites.
@@ -647,6 +649,9 @@ def check_deprecated(param, option, suggestion):
             else self.params['format'] if callable(self.params['format'])
             else self.build_format_selector(self.params['format']))
 
+        # Set http_headers defaults according to std_headers
+        self.params['http_headers'] = merge_headers(std_headers, self.params.get('http_headers', {}))
+
         self._setup_opener()
 
         if auto_init:
@@ -2250,8 +2255,7 @@ def restore_last_token(self):
         return _build_selector_function(parsed_selector)
 
     def _calc_headers(self, info_dict):
-        res = std_headers.copy()
-        res.update(info_dict.get('http_headers') or {})
+        res = merge_headers(self.params['http_headers'], info_dict.get('http_headers') or {})
 
         cookies = self._calc_cookies(info_dict)
         if cookies:
diff --git a/yt_dlp/__init__.py b/yt_dlp/__init__.py
index c87c5b6df9..926b5cad34 100644
--- a/yt_dlp/__init__.py
+++ b/yt_dlp/__init__.py
@@ -41,6 +41,7 @@
     SameFileError,
     setproctitle,
     std_headers,
+    traverse_obj,
     write_string,
 )
 from .update import run_update
@@ -75,20 +76,15 @@ def _real_main(argv=None):
     parser, opts, args = parseOpts(argv)
     warnings, deprecation_warnings = [], []
 
-    # Set user agent
     if opts.user_agent is not None:
-        std_headers['User-Agent'] = opts.user_agent
-
-    # Set referer
+        opts.headers.setdefault('User-Agent', opts.user_agent)
     if opts.referer is not None:
-        std_headers['Referer'] = opts.referer
-
-    # Custom HTTP headers
-    std_headers.update(opts.headers)
+        opts.headers.setdefault('Referer', opts.referer)
 
     # Dump user agent
     if opts.dump_user_agent:
-        write_string(std_headers['User-Agent'] + '\n', out=sys.stdout)
+        ua = traverse_obj(opts.headers, 'User-Agent', casesense=False, default=std_headers['User-Agent'])
+        write_string(f'{ua}\n', out=sys.stdout)
         sys.exit(0)
 
     # Batch file verification
@@ -767,6 +763,7 @@ def report_deprecation(val, old, new=None):
         'legacyserverconnect': opts.legacy_server_connect,
         'nocheckcertificate': opts.no_check_certificate,
         'prefer_insecure': opts.prefer_insecure,
+        'http_headers': opts.headers,
         'proxy': opts.proxy,
         'socket_timeout': opts.socket_timeout,
         'bidi_workaround': opts.bidi_workaround,
diff --git a/yt_dlp/extractor/instagram.py b/yt_dlp/extractor/instagram.py
index a2cc9f748b..3bb786d6a3 100644
--- a/yt_dlp/extractor/instagram.py
+++ b/yt_dlp/extractor/instagram.py
@@ -17,7 +17,6 @@
     get_element_by_attribute,
     int_or_none,
     lowercase_escape,
-    std_headers,
     str_or_none,
     str_to_int,
     traverse_obj,
@@ -503,7 +502,7 @@ def _extract_graphql(self, data, url):
                     '%s' % rhx_gis,
                     '',
                     '%s:%s' % (rhx_gis, csrf_token),
-                    '%s:%s:%s' % (rhx_gis, csrf_token, std_headers['User-Agent']),
+                    '%s:%s:%s' % (rhx_gis, csrf_token, self.get_param('http_headers')['User-Agent']),
                 ]
 
             # try all of the ways to generate a GIS query, and not only use the
diff --git a/yt_dlp/extractor/mildom.py b/yt_dlp/extractor/mildom.py
index ddeaa70218..b5a2e17f2c 100644
--- a/yt_dlp/extractor/mildom.py
+++ b/yt_dlp/extractor/mildom.py
@@ -8,7 +8,6 @@
 
 from .common import InfoExtractor
 from ..utils import (
-    std_headers,
     update_url_query,
     random_uuidv4,
     try_get,
@@ -70,7 +69,7 @@ def _fetch_dispatcher_config(self):
                         'clu': '',
                         'wh': '1919*810',
                         'rtm': self.iso_timestamp(),
-                        'ua': std_headers['User-Agent'],
+                        'ua': self.get_param('http_headers')['User-Agent'],
                     }).encode('utf8')).decode('utf8').replace('\n', ''),
                 }).encode('utf8'))
             self._DISPATCHER_CONFIG = self._parse_json(base64.b64decode(tmp['data']), 'initialization')
diff --git a/yt_dlp/extractor/openload.py b/yt_dlp/extractor/openload.py
index 6ec54509b6..36927009d5 100644
--- a/yt_dlp/extractor/openload.py
+++ b/yt_dlp/extractor/openload.py
@@ -16,7 +16,6 @@
     ExtractorError,
     get_exe_version,
     is_outdated_version,
-    std_headers,
     Popen,
 )
 
@@ -208,7 +207,7 @@ def get(self, url, html=None, video_id=None, note=None, note2='Executing JS on w
 
         replaces = self.options
         replaces['url'] = url
-        user_agent = headers.get('User-Agent') or std_headers['User-Agent']
+        user_agent = headers.get('User-Agent') or self.get_param('http_headers')['User-Agent']
         replaces['ua'] = user_agent.replace('"', '\\"')
         replaces['jscode'] = jscode
 
diff --git a/yt_dlp/extractor/rtve.py b/yt_dlp/extractor/rtve.py
index af1bb943d5..7a1dc6f326 100644
--- a/yt_dlp/extractor/rtve.py
+++ b/yt_dlp/extractor/rtve.py
@@ -17,7 +17,6 @@
     qualities,
     remove_end,
     remove_start,
-    std_headers,
     try_get,
 )
 
@@ -71,7 +70,7 @@ class RTVEALaCartaIE(InfoExtractor):
     }]
 
     def _real_initialize(self):
-        user_agent_b64 = base64.b64encode(std_headers['User-Agent'].encode('utf-8')).decode('utf-8')
+        user_agent_b64 = base64.b64encode(self.get_param('http_headers')['User-Agent'].encode('utf-8')).decode('utf-8')
         self._manager = self._download_json(
             'http://www.rtve.es/odin/loki/' + user_agent_b64,
             None, 'Fetching manager info')['manager']
diff --git a/yt_dlp/extractor/vimeo.py b/yt_dlp/extractor/vimeo.py
index 1a9fd00e40..77ffb4bfbf 100644
--- a/yt_dlp/extractor/vimeo.py
+++ b/yt_dlp/extractor/vimeo.py
@@ -28,7 +28,6 @@
     parse_qs,
     sanitized_Request,
     smuggle_url,
-    std_headers,
     str_or_none,
     try_get,
     unified_timestamp,
@@ -758,7 +757,7 @@ def _try_album_password(self, url):
 
     def _real_extract(self, url):
         url, data = unsmuggle_url(url, {})
-        headers = std_headers.copy()
+        headers = self.get_param('http_headers').copy()
         if 'http_headers' in data:
             headers.update(data['http_headers'])
         if 'Referer' not in headers:
diff --git a/yt_dlp/options.py b/yt_dlp/options.py
index 9908f39752..17d8d5da69 100644
--- a/yt_dlp/options.py
+++ b/yt_dlp/options.py
@@ -860,17 +860,16 @@ def _dict_from_options_callback(
     workarounds.add_option(
         '--user-agent',
         metavar='UA', dest='user_agent',
-        help='Specify a custom user agent')
+        help=optparse.SUPPRESS_HELP)
     workarounds.add_option(
         '--referer',
         metavar='URL', dest='referer', default=None,
-        help='Specify a custom referer, use if the video access is restricted to one domain',
-    )
+        help=optparse.SUPPRESS_HELP)
     workarounds.add_option(
         '--add-header',
         metavar='FIELD:VALUE', dest='headers', default={}, type='str',
         action='callback', callback=_dict_from_options_callback,
-        callback_kwargs={'multiple_keys': False, 'process_key': None},
+        callback_kwargs={'multiple_keys': False},
         help='Specify a custom HTTP header and its value, separated by a colon ":". You can use this option multiple times',
     )
     workarounds.add_option(
diff --git a/yt_dlp/utils.py b/yt_dlp/utils.py
index ef2c6bb245..be0c69d8fb 100644
--- a/yt_dlp/utils.py
+++ b/yt_dlp/utils.py
@@ -1372,7 +1372,7 @@ def http_request(self, req):
         if url != url_escaped:
             req = update_Request(req, url=url_escaped)
 
-        for h, v in std_headers.items():
+        for h, v in self._params.get('http_headers', std_headers).items():
             # Capitalize is needed because of Python bug 2275: http://bugs.python.org/issue2275
             # The dict keys are capitalized because of this bug by urllib
             if h.capitalize() not in req.headers:
@@ -5436,3 +5436,8 @@ def _cancel_all_tasks(loop):
 
 
 has_websockets = bool(compat_websockets)
+
+
+def merge_headers(*dicts):
+    """Merge dicts of network headers case insensitively, prioritizing the latter ones"""
+    return {k.capitalize(): v for k, v in itertools.chain.from_iterable(map(dict.items, dicts))}