diff --git a/src/domain/session/room/timeline/tiles/CallTile.js b/src/domain/session/room/timeline/tiles/CallTile.js
index ffb9ef59..37be05be 100644
--- a/src/domain/session/room/timeline/tiles/CallTile.js
+++ b/src/domain/session/room/timeline/tiles/CallTile.js
@@ -94,7 +94,7 @@ export class CallTile extends SimpleTile {
     }
 
     get canJoin() {
-        return this._call && !this._call.hasJoined;
+        return this._call && !this._call.hasJoined && !this._call.usesFoci;
     }
 
     get canLeave() {
diff --git a/src/matrix/calls/group/GroupCall.ts b/src/matrix/calls/group/GroupCall.ts
index 90c4d982..9ef2e068 100644
--- a/src/matrix/calls/group/GroupCall.ts
+++ b/src/matrix/calls/group/GroupCall.ts
@@ -190,7 +190,7 @@ export class GroupCall extends EventEmitter<{change: never}> {
 
     join(localMedia: LocalMedia, log?: ILogItem): Promise<void> {
         return this.options.logger.wrapOrRun(log, "Call.join", async joinLog => {
-            if (this._state !== GroupCallState.Created || this.joinedData) {
+            if (this._state !== GroupCallState.Created || this.joinedData || this.usesFoci) {
                 return;
             }
             const logItem = this.options.logger.child({