diff --git a/modules/prebidServerBidAdapter/index.js b/modules/prebidServerBidAdapter/index.js
index 3cae4497354..776ad99fa25 100644
--- a/modules/prebidServerBidAdapter/index.js
+++ b/modules/prebidServerBidAdapter/index.js
@@ -483,7 +483,11 @@ export function PrebidServer() {
           done();
           doClientSideSyncs(requestedBidders, gdprConsent, uspConsent, gppConsent);
         },
-        onError: done,
+        onError(msg, error) {
+          logError(`Prebid server call failed: '${msg}'`, error);
+          bidRequests.forEach(bidderRequest => events.emit(CONSTANTS.EVENTS.BIDDER_ERROR, {error, bidderRequest}));
+          done();
+        },
         onBid: function ({adUnit, bid}) {
           const metrics = bid.metrics = s2sBidRequest.metrics.fork().renameWith();
           metrics.checkpoint('addBidResponse');
diff --git a/test/spec/modules/prebidServerBidAdapter_spec.js b/test/spec/modules/prebidServerBidAdapter_spec.js
index c823366dbce..4b783803507 100644
--- a/test/spec/modules/prebidServerBidAdapter_spec.js
+++ b/test/spec/modules/prebidServerBidAdapter_spec.js
@@ -2876,6 +2876,15 @@ describe('S2S Adapter', function () {
       events.emit.restore();
     });
 
+    it('triggers BIDDER_ERROR on server error', () => {
+      config.setConfig({ s2sConfig: CONFIG });
+      adapter.callBids(REQUEST, BID_REQUESTS, addBidResponse, done, ajax);
+      server.requests[0].respond(400, {}, {});
+      BID_REQUESTS.forEach(bidderRequest => {
+        sinon.assert.calledWith(events.emit, CONSTANTS.EVENTS.BIDDER_ERROR, sinon.match({bidderRequest}))
+      })
+    })
+
     // TODO: test dependent on pbjs_api_spec.  Needs to be isolated
     it('does not call addBidResponse and calls done when ad unit not set', function () {
       config.setConfig({ s2sConfig: CONFIG });