diff --git a/src/matrixeventprocessor.ts b/src/matrixeventprocessor.ts
index d9311cc3af161f52d5d08e0349191c1ba22f7f0d..0c9ea10ed0406a6369a42d08adb1247a2778330e 100644
--- a/src/matrixeventprocessor.ts
+++ b/src/matrixeventprocessor.ts
@@ -212,6 +212,7 @@ export class MatrixEventProcessor {
             const membership = event.content!.membership;
             if (membership === "join") {
                 this.mxUserProfileCache.delete(`${event.room_id}:${event.sender}`);
+                this.mxUserProfileCache.delete(`${event.sender}`);
                 if (event.content!.displayname) {
                     this.mxUserProfileCache.set(`${event.room_id}:${event.sender}`, {
                         avatar_url: event.content!.avatar_url,