diff --git a/spec/unit/matrixrtc/mocks.ts b/spec/unit/matrixrtc/mocks.ts
index 5b6641cf3..bff745162 100644
--- a/spec/unit/matrixrtc/mocks.ts
+++ b/spec/unit/matrixrtc/mocks.ts
@@ -170,9 +170,7 @@ export function mockRTCEvent(
             timestamp,
             !stickyDuration && "device_id" in membershipData ? `_${sender}_${membershipData.device_id}` : "",
         ),
-        unstableStickyContent: {
-            duration_ms: stickyDuration,
-        },
+        unstableStickyExpiresAt:stickyDuration,
     } as unknown as MatrixEvent;
 }
 
diff --git a/src/matrixrtc/MatrixRTCSessionManager.ts b/src/matrixrtc/MatrixRTCSessionManager.ts
index 507dc54d2..c586ffce9 100644
--- a/src/matrixrtc/MatrixRTCSessionManager.ts
+++ b/src/matrixrtc/MatrixRTCSessionManager.ts
@@ -116,7 +116,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
     };
 
     private onEvent = (event: MatrixEvent): void => {
-        if (!event.unstableStickyContent?.duration_ms) {
+        if (!event.unstableStickyExpiresAt) {
             return; // Not sticky, not interested.
         }
         if (event.getType() !== EventType.GroupCallMemberPrefix) {