diff --git a/src/widget.ts b/src/widget.ts
index f2d2b2907..d3c98867f 100644
--- a/src/widget.ts
+++ b/src/widget.ts
@@ -138,7 +138,7 @@ export const widget = ((): WidgetHelpers | null => {
       const sendState = [
         userId, // Legacy call membership events
         `_${userId}_${deviceId}`, // Session membership events
-        `${userId}_${deviceId}`, // MSC3779 session membership events
+        `${userId}_${deviceId}`, // The above with no leading underscore, for room versions whose auth rules allow it
       ].map((stateKey) => ({
         eventType: EventType.GroupCallMemberPrefix,
         stateKey,