diff --git a/mautrix_telegram/example-config.yaml b/mautrix_telegram/example-config.yaml
index 06b0e946..b37b0f21 100644
--- a/mautrix_telegram/example-config.yaml
+++ b/mautrix_telegram/example-config.yaml
@@ -272,8 +272,15 @@ bridge:
         # Default to encryption, force-enable encryption in all portals the bridge creates
         # This will cause the bridge bot to be in private chats for the encryption to work properly.
         default: false
-        # Whether to use MSC2409/MSC3202 instead of /sync long polling for receiving encryption-related data.
+        # Whether to use MSC3202/MSC4203 instead of /sync long polling for receiving encryption-related data.
+        # This option is not yet compatible with standard Matrix servers like Synapse and should not be used.
+        # Changing this option requires updating the appservice registration file.
         appservice: false
+        # Whether to use MSC4190 instead of appservice login to create the bridge bot device.
+        # Requires the homeserver to support MSC4190 and the device masquerading parts of MSC3202.
+        # Only relevant when using end-to-bridge encryption, required when using encryption with next-gen auth (MSC3861).
+        # Changing this option requires updating the appservice registration file.
+        msc4190: false
         # Require encryption, drop any unencrypted messages.
         require: false
         # Enable key sharing? If enabled, key requests for rooms where users are in will be fulfilled.
diff --git a/requirements.txt b/requirements.txt
index be50ccc2..6a470406 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ python-magic>=0.4,<0.5
 commonmark>=0.8,<0.10
 aiohttp>=3,<4
 yarl>=1,<2
-mautrix>=0.20.6,<0.21
+mautrix>=0.20.8b1,<0.21
 tulir-telethon==1.37.0a1
 asyncpg>=0.20,<1
 mako>=1,<2