--- a/devtools/client/netmonitor/src/reducers/requests.js
+++ b/devtools/client/netmonitor/src/reducers/requests.js
@@ -163,18 +163,18 @@ function requestsReducer(state = new Req
           request[key] = value;
 
           switch (key) {
             case "url":
               // Compute the additional URL details
               request.urlDetails = getUrlDetails(value);
               break;
             case "totalTime":
-              const endedMillis = request.startedMillis + value;
-              lastEndedMillis = Math.max(lastEndedMillis, endedMillis);
+              request.endedMillis = request.startedMillis + value;
+              lastEndedMillis = Math.max(lastEndedMillis, request.endedMillis);
               break;
             case "requestPostData":
               request.requestHeadersFromUploadStream = {
                 headers: [],
                 headersSize: 0,
               };
               break;
           }