diff --git a/libraries/pbsExtensions/processors/params.js b/libraries/pbsExtensions/processors/params.js
index 010ffa5b372..dbfbb928953 100644
--- a/libraries/pbsExtensions/processors/params.js
+++ b/libraries/pbsExtensions/processors/params.js
@@ -1,17 +1,7 @@
-import {auctionManager} from '../../../src/auctionManager.js';
-import adapterManager from '../../../src/adapterManager.js';
 import {deepSetValue} from '../../../src/utils.js';
 
-export function setImpBidParams(
-  imp, bidRequest, context,
-  {adUnit, bidderRequests, index = auctionManager.index, bidderRegistry = adapterManager.bidderRegistry} = {}) {
+export function setImpBidParams(imp, bidRequest) {
   let params = bidRequest.params;
-  const adapter = bidderRegistry[bidRequest.bidder];
-  if (adapter && adapter.getSpec().transformBidParams) {
-    adUnit = adUnit || index.getAdUnit(bidRequest);
-    bidderRequests = bidderRequests || [context.bidderRequest];
-    params = adapter.getSpec().transformBidParams(params, true, adUnit, bidderRequests);
-  }
   if (params) {
     deepSetValue(
       imp,
diff --git a/test/spec/modules/prebidServerBidAdapter_spec.js b/test/spec/modules/prebidServerBidAdapter_spec.js
index f2afdf4e63b..d090a872d9c 100644
--- a/test/spec/modules/prebidServerBidAdapter_spec.js
+++ b/test/spec/modules/prebidServerBidAdapter_spec.js
@@ -1746,39 +1746,6 @@ describe('S2S Adapter', function () {
       });
     });
 
-    it('converts appnexus params to expected format for PBS', function () {
-      const s2sConfig = Object.assign({}, CONFIG, {
-        endpoint: {
-          p1Consent: 'https://prebid.adnxs.com/pbs/v1/openrtb2/auction'
-        }
-      });
-      config.setConfig({ s2sConfig: s2sConfig });
-
-      Object.assign(BID_REQUESTS[0].bids[0].params, {
-        usePaymentRule: true,
-        keywords: {
-          foo: ['bar', 'baz'],
-          fizz: ['buzz']
-        }
-      })
-
-      adapter.callBids(REQUEST, BID_REQUESTS, addBidResponse, done, ajax);
-      const requestBid = JSON.parse(server.requests[0].requestBody);
-
-      const requestParams = requestBid.imp[0].ext.prebid.bidder;
-      expect(requestParams.appnexus).to.exist;
-      expect(requestParams.appnexus.placement_id).to.exist.and.to.equal(10433394);
-      expect(requestParams.appnexus.use_pmt_rule).to.exist.and.to.be.true;
-      expect(requestParams.appnexus.member).to.exist;
-      expect(requestParams.appnexus.keywords).to.exist.and.to.deep.equal([{
-        key: 'foo',
-        value: ['bar', 'baz']
-      }, {
-        key: 'fizz',
-        value: ['buzz']
-      }]);
-    });
-
     describe('cookie sync', () => {
       let s2sConfig, bidderReqs;
 
diff --git a/test/spec/ortbConverter/pbsExtensions/params_spec.js b/test/spec/ortbConverter/pbsExtensions/params_spec.js
index 73b92a0755d..d1b36c18b49 100644
--- a/test/spec/ortbConverter/pbsExtensions/params_spec.js
+++ b/test/spec/ortbConverter/pbsExtensions/params_spec.js
@@ -34,63 +34,5 @@ describe('pbjs -> ortb bid params to imp[].ext.prebid.BIDDER', () => {
 
   it('has no effect if bidRequest has no params', () => {
     expect(setParams({bidder: 'mockBidder'})).to.eql({});
-  })
-
-  describe('when adapter provides transformBidParams', () => {
-    let transform, bidderRequest;
-    beforeEach(() => {
-      bidderRequest = {bidderCode: 'mockBidder'};
-      transform = sinon.stub().callsFake((p) => Object.assign({transformed: true}, p));
-      bidderRegistry.mockBidder = {
-        getSpec() {
-          return {
-            transformBidParams: transform
-          }
-        }
-      }
-    })
-
-    it('runs params through transform', () => {
-      expect(setParams({bidder: 'mockBidder', params: {a: 'param'}}, {bidderRequest})).to.eql({
-        ext: {
-          prebid: {
-            bidder: {
-              mockBidder: {
-                a: 'param',
-                transformed: true
-              }
-            }
-          }
-        }
-      });
-    });
-
-    it('runs through transform even if bid has no params', () => {
-      expect(setParams({bidder: 'mockBidder'}, {bidderRequest})).to.eql({
-        ext: {
-          prebid: {
-            bidder: {
-              mockBidder: {
-                transformed: true
-              }
-            }
-          }
-        }
-      })
-    })
-
-    it('by default, passes adUnit from index, bidderRequest from context', () => {
-      const params = {a: 'param'};
-      setParams({bidder: 'mockBidder', params}, {bidderRequest});
-      sinon.assert.calledWith(transform, params, true, adUnit, [bidderRequest])
-    });
-
-    it('uses provided adUnit, bidderRequests', () => {
-      const adUnit = {code: 'other-ad-unit'};
-      const bidderRequests = [{bidderCode: 'one'}, {bidderCode: 'two'}];
-      const params = {a: 'param'};
-      setParams({bidder: 'mockBidder', params}, {}, {adUnit, bidderRequests});
-      sinon.assert.calledWith(transform, params, true, adUnit, bidderRequests);
-    })
   });
 });