diff --git a/config/default.yaml b/config/default.yaml
index 17598d0..eca8f2d 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -21,14 +21,13 @@ pantalaimon:
 # The directory the bot should store various bits of information in
 dataPath: "/data/storage"
 
-# Whether the bot should autojoin rooms it is invited to or not
-autojoin: true
+# If true (the default), only users in the `managementRoom` can invite the bot
+# to new rooms.
+autojoinOnlyIfManager: true
 
-# If `autojoin` is true, this defines whether anyone can invite the bot (the
-# default), or only those in the `managementRoom` below. Generally this option
-# should be set to true (only allow people in the management room to do invites)
-# when using autojoin.
-autojoinOnlyIfManager: false
+# If `autojoinOnlyIfManager` is false, only the members in this group can invite
+# the bot to new rooms.
+acceptInvitesFromGroup: '+example:example.org'
 
 # The room ID where people can use the bot. The bot has no access controls, so
 # anyone in this room can use the bot - secure your room!
diff --git a/src/config.ts b/src/config.ts
index 768af67..b1a5668 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -26,7 +26,7 @@ interface IConfig {
         password: string;
     };
     dataPath: string;
-    autojoin: boolean;
+    acceptInvitesFromGroup: string;
     autojoinOnlyIfManager: boolean;
     managementRoom: string;
     verboseLogging: boolean;
@@ -66,7 +66,7 @@ const defaultConfig: IConfig = {
         password: "",
     },
     dataPath: "/data/storage",
-    autojoin: false,
+    acceptInvitesFromGroup: '+example:example.org',
     autojoinOnlyIfManager: false,
     managementRoom: "!noop:example.org",
     verboseLogging: false,
diff --git a/src/index.ts b/src/index.ts
index 087c1ea..389cee3 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -16,7 +16,6 @@ limitations under the License.
 
 import * as path from "path";
 import {
-    AutojoinRoomsMixin,
     LogLevel,
     LogService,
     MatrixClient,
@@ -30,7 +29,7 @@ import BanList from "./models/BanList";
 import { Mjolnir } from "./Mjolnir";
 import { logMessage } from "./LogProxy";
 import { MembershipEvent } from "matrix-bot-sdk/lib/models/events/MembershipEvent";
-import {BanListServer} from "./server/BanListServer";
+import { BanListServer } from "./server/BanListServer";
 
 config.RUNTIME = {client: null};
 
@@ -52,18 +51,20 @@ LogService.info("index", "Starting bot...");
 
     config.RUNTIME.client = client;
 
-    if (config.autojoin) {
+    client.on("room.invite", async (roomId: string, inviteEvent: any) => {
+        const membershipEvent = new MembershipEvent(inviteEvent);
+
         if (config.autojoinOnlyIfManager) {
-            client.on("room.invite", async (roomId: string, inviteEvent: any) => {
-                const membershipEvent = new MembershipEvent(inviteEvent);
-                const managers = await client.getJoinedRoomMembers(config.managementRoom);
-                if (!managers.includes(membershipEvent.sender)) return; // ignore invite
-                return client.joinRoom(roomId);
-            });
+            const managers = await client.getJoinedRoomMembers(config.managementRoom);
+            if (!managers.includes(membershipEvent.sender)) return; // ignore invite
         } else {
-            AutojoinRoomsMixin.setupOnClient(client);
+            const groupMembers = await client.unstableApis.getGroupUsers(config.acceptInvitesFromGroup);
+            const userIds = groupMembers.map(m => m.user_id);
+            if (!userIds.includes(membershipEvent.sender)) return; // ignore invite
         }
-    }
+
+        return client.joinRoom(roomId);
+    });
 
     const banLists: BanList[] = [];
     const protectedRooms: { [roomId: string]: string } = {};