diff --git a/yt_dlp/YoutubeDL.py b/yt_dlp/YoutubeDL.py
index 5abcb4635..7ed01bf84 100644
--- a/yt_dlp/YoutubeDL.py
+++ b/yt_dlp/YoutubeDL.py
@@ -581,8 +581,9 @@ class YoutubeDL:
         'vbr', 'fps', 'vcodec', 'container', 'filesize', 'filesize_approx', 'rows', 'columns',
         'player_url', 'protocol', 'fragment_base_url', 'fragments', 'is_from_start', 'is_dash_periods', 'request_data',
         'preference', 'language', 'language_preference', 'quality', 'source_preference', 'cookies',
-        'http_headers', 'stretched_ratio', 'no_resume', 'has_drm', 'extra_param_to_segment_url', 'hls_aes', 'downloader_options',
-        'page_url', 'app', 'play_path', 'tc_url', 'flash_version', 'rtmp_live', 'rtmp_conn', 'rtmp_protocol', 'rtmp_real_time',
+        'http_headers', 'stretched_ratio', 'no_resume', 'has_drm', 'extra_param_to_segment_url', 'extra_param_to_key_url',
+        'hls_aes', 'downloader_options', 'page_url', 'app', 'play_path', 'tc_url', 'flash_version',
+        'rtmp_live', 'rtmp_conn', 'rtmp_protocol', 'rtmp_real_time',
     }
     _deprecated_multivalue_fields = {
         'album_artist': 'album_artists',
diff --git a/yt_dlp/downloader/external.py b/yt_dlp/downloader/external.py
index 8b45c671a..63c108569 100644
--- a/yt_dlp/downloader/external.py
+++ b/yt_dlp/downloader/external.py
@@ -108,7 +108,7 @@ def supports(cls, info_dict):
         return all((
             not info_dict.get('to_stdout') or Features.TO_STDOUT in cls.SUPPORTED_FEATURES,
             '+' not in info_dict['protocol'] or Features.MULTIPLE_FORMATS in cls.SUPPORTED_FEATURES,
-            not traverse_obj(info_dict, ('hls_aes', ...), 'extra_param_to_segment_url'),
+            not traverse_obj(info_dict, ('hls_aes', ...), 'extra_param_to_segment_url', 'extra_param_to_key_url'),
             all(proto in cls.SUPPORTED_PROTOCOLS for proto in info_dict['protocol'].split('+')),
         ))
 
diff --git a/yt_dlp/downloader/hls.py b/yt_dlp/downloader/hls.py
index 9cb4f014c..0a00d5dab 100644
--- a/yt_dlp/downloader/hls.py
+++ b/yt_dlp/downloader/hls.py
@@ -160,10 +160,12 @@ def is_ad_fragment_end(s):
         extra_state = ctx.setdefault('extra_state', {})
 
         format_index = info_dict.get('format_index')
-        extra_query = None
-        extra_param_to_segment_url = info_dict.get('extra_param_to_segment_url')
-        if extra_param_to_segment_url:
-            extra_query = urllib.parse.parse_qs(extra_param_to_segment_url)
+        extra_segment_query = None
+        if extra_param_to_segment_url := info_dict.get('extra_param_to_segment_url'):
+            extra_segment_query = urllib.parse.parse_qs(extra_param_to_segment_url)
+        extra_key_query = None
+        if extra_param_to_key_url := info_dict.get('extra_param_to_key_url'):
+            extra_key_query = urllib.parse.parse_qs(extra_param_to_key_url)
         i = 0
         media_sequence = 0
         decrypt_info = {'METHOD': 'NONE'}
@@ -190,8 +192,8 @@ def is_ad_fragment_end(s):
                     if frag_index <= ctx['fragment_index']:
                         continue
                     frag_url = urljoin(man_url, line)
-                    if extra_query:
-                        frag_url = update_url_query(frag_url, extra_query)
+                    if extra_segment_query:
+                        frag_url = update_url_query(frag_url, extra_segment_query)
 
                     fragments.append({
                         'frag_index': frag_index,
@@ -212,8 +214,8 @@ def is_ad_fragment_end(s):
                     frag_index += 1
                     map_info = parse_m3u8_attributes(line[11:])
                     frag_url = urljoin(man_url, map_info.get('URI'))
-                    if extra_query:
-                        frag_url = update_url_query(frag_url, extra_query)
+                    if extra_segment_query:
+                        frag_url = update_url_query(frag_url, extra_segment_query)
 
                     if map_info.get('BYTERANGE'):
                         splitted_byte_range = map_info.get('BYTERANGE').split('@')
@@ -244,8 +246,10 @@ def is_ad_fragment_end(s):
                             decrypt_info['KEY'] = external_aes_key
                         else:
                             decrypt_info['URI'] = urljoin(man_url, decrypt_info['URI'])
-                            if extra_query:
-                                decrypt_info['URI'] = update_url_query(decrypt_info['URI'], extra_query)
+                            if extra_key_query or extra_segment_query:
+                                # Fall back to extra_segment_query to key for backwards compat
+                                decrypt_info['URI'] = update_url_query(
+                                    decrypt_info['URI'], extra_key_query or extra_segment_query)
                             if decrypt_url != decrypt_info['URI']:
                                 decrypt_info['KEY'] = None
 
diff --git a/yt_dlp/extractor/common.py b/yt_dlp/extractor/common.py
index 2799747ec..e5efd08b4 100644
--- a/yt_dlp/extractor/common.py
+++ b/yt_dlp/extractor/common.py
@@ -234,7 +234,14 @@ class InfoExtractor:
                                  'maybe' if the format may have DRM and has to be tested before download.
                     * extra_param_to_segment_url  A query string to append to each
                                  fragment's URL, or to update each existing query string
-                                 with. Only applied by the native HLS/DASH downloaders.
+                                 with. If it is an HLS stream with an AES-128 decryption key,
+                                 the query paramaters will be passed to the key URI as well,
+                                 unless there is an `extra_param_to_key_url` given,
+                                 or unless an external key URI is provided via `hls_aes`.
+                                 Only applied by the native HLS/DASH downloaders.
+                    * extra_param_to_key_url  A query string to append to the URL
+                                 of the format's HLS AES-128 decryption key.
+                                 Only applied by the native HLS downloader.
                     * hls_aes    A dictionary of HLS AES-128 decryption information
                                  used by the native HLS downloader to override the
                                  values in the media playlist when an '#EXT-X-KEY' tag