diff --git a/src/auction.js b/src/auction.js
index f5f7e3a9eec..f37fead883b 100644
--- a/src/auction.js
+++ b/src/auction.js
@@ -48,7 +48,7 @@
  * @property {function(): void} callBids - sends requests to all adapters for bids
  */
 
-import { uniques, timestamp, adUnitsFilter, delayExecution, getBidderRequest } from './utils';
+import { uniques, flatten, timestamp, adUnitsFilter, delayExecution, getBidderRequest } from './utils';
 import { getPriceBucketString } from './cpmBucketManager';
 import { NATIVE_KEYS } from './native';
 import { getCacheUrl, store } from './videoCache';
@@ -88,7 +88,7 @@ export function newAuction({adUnits, adUnitCodes, callback, cbTimeout, labels})
   let _bidderRequests = [];
   let _bidsReceived = [];
   let _auctionStart;
-  let _auctionId = utils.getUniqueIdentifierStr();
+  let _auctionId = utils.generateUUID();
   let _auctionStatus;
   let _callback = callback;
   let _timer;
@@ -132,28 +132,14 @@ export function newAuction({adUnits, adUnitCodes, callback, cbTimeout, labels})
 
       if (timedOut) {
         utils.logMessage(`Auction ${_auctionId} timedOut`);
-        const timedOutBidders = getTimedOutBidders();
+        const timedOutBidders = getTimedOutBids(_bidderRequests, _bidsReceived);
         if (timedOutBidders.length) {
-          events.emit(CONSTANTS.EVENTS.BID_TIMEOUT, { timedOutBidders, auctionId: _auctionId });
+          events.emit(CONSTANTS.EVENTS.BID_TIMEOUT, timedOutBidders);
         }
       }
     }
   }
 
-  function getTimedOutBidders() {
-    return _bidderRequests
-      .map((bidSet) => {
-        return bidSet.bidderCode;
-      })
-      .filter(uniques)
-      .filter(bidder => _bidsReceived
-        .map((bid) => {
-          return bid.bidder;
-        })
-        .filter(uniques)
-        .indexOf(bidder) < 0);
-  };
-
   function done(bidRequestId) {
     var innerBidRequestId = bidRequestId;
     return delayExecution(function() {
@@ -458,3 +444,41 @@ function groupByPlacement(bidsByPlacement, bid) {
   bidsByPlacement[bid.adUnitCode].bids.push(bid);
   return bidsByPlacement;
 }
+
+/**
+ * Returns a list of bids that we haven't received a response yet
+ * @param {BidRequest[]} bidderRequests List of bids requested for auction instance
+ * @param {BidReceived[]} bidsReceived List of bids received for auction instance
+ *
+ * @typedef {Object} TimedOutBid
+ * @property {string} bidId The id representing the bid
+ * @property {string} bidder The string name of the bidder
+ * @property {string} adUnitCode The code used to uniquely identify the ad unit on the publisher's page
+ * @property {string} auctionId The id representing the auction
+ *
+ * @return {Array<TimedOutBid>} List of bids that Prebid hasn't received a response for
+ */
+function getTimedOutBids(bidderRequests, bidsReceived) {
+  const bidRequestedCodes = bidderRequests
+    .map(bid => bid.bidderCode)
+    .filter(uniques);
+
+  const bidReceivedCodes = bidsReceived
+    .map(bid => bid.bidder)
+    .filter(uniques);
+
+  const timedOutBidderCodes = bidRequestedCodes
+    .filter(bidder => !bidReceivedCodes.includes(bidder));
+
+  const timedOutBids = bidderRequests
+    .map(bid => (bid.bids || []).filter(bid => timedOutBidderCodes.includes(bid.bidder)))
+    .reduce(flatten, [])
+    .map(bid => ({
+      bidId: bid.bidId,
+      bidder: bid.bidder,
+      adUnitCode: bid.adUnitCode,
+      auctionId: bid.auctionId,
+    }));
+
+  return timedOutBids;
+}
diff --git a/test/spec/unit/pbjs_api_spec.js b/test/spec/unit/pbjs_api_spec.js
index 613074e59f9..223752d2e57 100644
--- a/test/spec/unit/pbjs_api_spec.js
+++ b/test/spec/unit/pbjs_api_spec.js
@@ -850,7 +850,7 @@ describe('Unit: Prebid Module', function () {
         };
 
         $$PREBID_GLOBAL$$.requestBids(requestObj);
-        let re = new RegExp('^Auction [0-9A-Za-z]+ timedOut$');
+        let re = new RegExp('^Auction [a-f0-9]{8}-?[a-f0-9]{4}-?4[a-f0-9]{3}-?[89ab][a-f0-9]{3}-?[a-f0-9]{12} timedOut$');
         clock.tick(requestObj.timeout - 1);
         assert.ok(logMessageSpy.neverCalledWith(sinon.match(re)), 'executeCallback not called');