diff --git a/modules/prebidServerBidAdapter.js b/modules/prebidServerBidAdapter.js
index 7120d67eb56..a4497b52b07 100644
--- a/modules/prebidServerBidAdapter.js
+++ b/modules/prebidServerBidAdapter.js
@@ -99,6 +99,25 @@ function PrebidServer() {
             }
           }
         });
+        // will collect any custom params and place them under bid.params.keywords attribute in the following manner for pbs to ingest properly
+        // "keywords":[{"key":"randomKey","value":["123456789"]},{"key":"single_test"},{"key":"myMultiVar","value":["myValue","124578"]}]
+        let kwArray = [];
+        Object.keys(bid.params).forEach(key => {
+          if (bid.bidder === 'appnexus' && (key !== 'member' && key !== 'invCode' && key !== 'placementId')) {
+            let kvObj = {};
+            kvObj.key = key
+            if (bid.params[key] !== null) {
+              if (Array.isArray(bid.params[key])) {
+                kvObj.value = bid.params[key].map(val => tryConvertString(val));
+              } else {
+                kvObj.value = [tryConvertString(bid.params[key])];
+              }
+            }
+            kwArray.push(kvObj);
+            delete bid.params[key];
+          }
+        });
+        bid.params.keywords = kwArray;
       });
     });
   }
diff --git a/test/spec/modules/prebidServerBidAdapter_spec.js b/test/spec/modules/prebidServerBidAdapter_spec.js
index 78eef4b016b..0403617a846 100644
--- a/test/spec/modules/prebidServerBidAdapter_spec.js
+++ b/test/spec/modules/prebidServerBidAdapter_spec.js
@@ -43,7 +43,10 @@ const REQUEST = {
           'bidder': 'appnexus',
           'params': {
             'placementId': '10433394',
-            'member': 123
+            'member': 123,
+            'randomKey': 123456789,
+            'single_test': null,
+            'myMultiVar': ['myValue', 124578]
           }
         }
       ]
@@ -201,6 +204,8 @@ describe('S2S Adapter', () => {
       const requestBid = JSON.parse(requests[0].requestBody);
       expect(requestBid.ad_units[0].bids[0].params.placementId).to.exist.and.to.be.a('number');
       expect(requestBid.ad_units[0].bids[0].params.member).to.exist.and.to.be.a('string');
+      expect(requestBid.ad_units[0].bids[0].params.keywords).to.exist.and.to.be.an('array').and.to.have.lengthOf(3);
+      expect(requestBid.ad_units[0].bids[0].params.keywords[0]).to.be.an('object').that.has.all.keys('key', 'value');
     });
   });