diff --git a/src/otel/OTelGroupCallMembership.ts b/src/otel/OTelGroupCallMembership.ts
index 53551b0..3c73916 100644
--- a/src/otel/OTelGroupCallMembership.ts
+++ b/src/otel/OTelGroupCallMembership.ts
@@ -205,13 +205,15 @@ export class OTelGroupCallMembership {
     const eventType = event.eventType as string;
     if (!eventType.startsWith("m.call")) return;
 
+    const callTrackingInfo = this.callsByCallId.get(call.callId);
+
     if (event.type === "toDevice") {
-      this.callMembershipSpan?.addEvent(
+      callTrackingInfo.span.addEvent(
         `matrix.sendToDeviceEvent_${event.eventType}`,
         flattenVoipEvent(event)
       );
     } else if (event.type === "sendEvent") {
-      this.callMembershipSpan?.addEvent(
+      callTrackingInfo.span.addEvent(
         `matrix.sendToRoomEvent_${event.eventType}`,
         flattenVoipEvent(event)
       );