diff --git a/src/models/Call.ts b/src/models/Call.ts
index c45bf94925..5b27f53766 100644
--- a/src/models/Call.ts
+++ b/src/models/Call.ts
@@ -654,6 +654,7 @@ export class ElementCall extends Call {
             analyticsID,
         });
 
+        if (client.isRoomEncrypted(groupCall.room.roomId)) params.append("perParticipantE2EE", "");
         if (SettingsStore.getValue("fallbackICEServerAllowed")) params.append("allowIceFallback", "");
         if (SettingsStore.getValue("feature_allow_screen_share_only_mode")) params.append("allowVoipWithNoMedia", "");
 
diff --git a/src/stores/widgets/StopGapWidgetDriver.ts b/src/stores/widgets/StopGapWidgetDriver.ts
index 8ae9196241..7b40272228 100644
--- a/src/stores/widgets/StopGapWidgetDriver.ts
+++ b/src/stores/widgets/StopGapWidgetDriver.ts
@@ -149,6 +149,12 @@ export class StopGapWidgetDriver extends WidgetDriver {
                 WidgetEventCapability.forStateEvent(EventDirection.Receive, "org.matrix.msc3401.call.member").raw,
             );
 
+            const sendRecvRoomEvents = ["io.element.call.encryption_key"];
+            for (const eventType of sendRecvRoomEvents) {
+                this.allowedCapabilities.add(WidgetEventCapability.forRoomEvent(EventDirection.Send, eventType).raw);
+                this.allowedCapabilities.add(WidgetEventCapability.forRoomEvent(EventDirection.Receive, eventType).raw);
+            }
+
             const sendRecvToDevice = [
                 EventType.CallInvite,
                 EventType.CallCandidates,