diff --git a/modules/rubiconBidAdapter.js b/modules/rubiconBidAdapter.js
index 4817d62348a..ffcc230ac13 100644
--- a/modules/rubiconBidAdapter.js
+++ b/modules/rubiconBidAdapter.js
@@ -1109,15 +1109,25 @@ function mapSizes(sizes) {
 
 /**
  * Test if bid has mediaType or mediaTypes set for video.
- * Also makes sure the video object is present in the rubicon bidder params
+ * Also checks if the video object is present in the rubicon bidder params
  * @param {BidRequest} bidRequest
  * @returns {boolean}
  */
-export function hasVideoMediaType(bidRequest) {
-  if (typeof deepAccess(bidRequest, 'params.video') !== 'object') {
-    return false;
+export function classifiedAsVideo(bidRequest) {
+  let isVideo = typeof deepAccess(bidRequest, `mediaTypes.${VIDEO}`) !== 'undefined';
+  let isBanner = typeof deepAccess(bidRequest, `mediaTypes.${BANNER}`) !== 'undefined';
+  let isMissingVideoParams = typeof deepAccess(bidRequest, 'params.video') !== 'object';
+  // If an ad has both video and banner types, a legacy implementation allows choosing video over banner
+  // based on whether or not there is a video object defined in the params
+  // Given this legacy implementation, other code depends on params.video being defined
+
+  if (isBanner && isMissingVideoParams) {
+    isVideo = false;
   }
-  return (typeof deepAccess(bidRequest, `mediaTypes.${VIDEO}`) !== 'undefined');
+  if (isVideo && isMissingVideoParams) {
+    deepSetValue(bidRequest, 'params.video', {});
+  }
+  return isVideo;
 }
 
 /**
@@ -1128,7 +1138,7 @@ export function hasVideoMediaType(bidRequest) {
  */
 function bidType(bid, log = false) {
   // Is it considered video ad unit by rubicon
-  if (hasVideoMediaType(bid)) {
+  if (classifiedAsVideo(bid)) {
     // Removed legacy mediaType support. new way using mediaTypes.video object is now required
     // We require either context as instream or outstream
     if (['outstream', 'instream'].indexOf(deepAccess(bid, `mediaTypes.${VIDEO}.context`)) === -1) {
diff --git a/test/spec/modules/rubiconBidAdapter_spec.js b/test/spec/modules/rubiconBidAdapter_spec.js
index fb1b336ef92..e81ef1c805f 100644
--- a/test/spec/modules/rubiconBidAdapter_spec.js
+++ b/test/spec/modules/rubiconBidAdapter_spec.js
@@ -4,7 +4,7 @@ import {
   getPriceGranularity,
   masSizeOrdering,
   resetUserSync,
-  hasVideoMediaType,
+  classifiedAsVideo,
   resetRubiConf
 } from 'modules/rubiconBidAdapter.js';
 import {parse as parseQuery} from 'querystring';
@@ -257,7 +257,7 @@ describe('the rubicon adapter', function () {
         context: 'instream'
       },
     };
-    bid.params.video = '';
+    bid.params.video = false;
   }
 
   function createVideoBidderRequestOutstream() {
@@ -2320,57 +2320,50 @@ describe('the rubicon adapter', function () {
         });
       });
 
-      describe('hasVideoMediaType', function () {
-        it('should return true if mediaType is video and size_id is set', function () {
+      describe('classifiedAsVideo', function () {
+        it('should return true if mediaTypes is video', function () {
           createVideoBidderRequest();
-          const legacyVideoTypeBidRequest = hasVideoMediaType(bidderRequest.bids[0]);
-          expect(legacyVideoTypeBidRequest).is.equal(true);
+          const bidClassifiedAsVideo = classifiedAsVideo(bidderRequest.bids[0]);
+          expect(bidClassifiedAsVideo).is.equal(true);
         });
 
         it('should return false if trying to use legacy mediaType with video', function () {
           createVideoBidderRequest();
           delete bidderRequest.bids[0].mediaTypes;
           bidderRequest.bids[0].mediaType = 'video';
-          const legacyVideoTypeBidRequest = hasVideoMediaType(bidderRequest.bids[0]);
+          const legacyVideoTypeBidRequest = classifiedAsVideo(bidderRequest.bids[0]);
           expect(legacyVideoTypeBidRequest).is.equal(false);
         });
 
-        it('should return false if bidRequest.mediaType is not equal to video', function () {
-          expect(hasVideoMediaType({
+        it('should return false if bid.mediaTypes is not equal to video', function () {
+          expect(classifiedAsVideo({
             mediaType: 'banner'
           })).is.equal(false);
         });
 
-        it('should return false if bidRequest.mediaType is not defined', function () {
-          expect(hasVideoMediaType({})).is.equal(false);
+        it('should return false if bid.mediaTypes is not defined', function () {
+          expect(classifiedAsVideo({})).is.equal(false);
         });
 
-        it('should return true if bidRequest.mediaTypes.video.context is instream and size_id is defined', function () {
-          expect(hasVideoMediaType({
-            mediaTypes: {
-              video: {
-                context: 'instream'
-              }
-            },
-            params: {
-              video: {
-                size_id: 7
-              }
-            }
-          })).is.equal(true);
+        it('Should return false if both banner and video mediaTypes are set and params.video is not an object', function () {
+          createVideoBidderRequestNoVideo();
+          let bid = bidderRequest.bids[0];
+          bid.mediaTypes.banner = {flag: true};
+          expect(classifiedAsVideo(bid)).to.equal(false);
+        });
+        it('Should return true if both banner and video mediaTypes are set and params.video is an object', function () {
+          createVideoBidderRequestNoVideo();
+          let bid = bidderRequest.bids[0];
+          bid.mediaTypes.banner = {flag: true};
+          bid.params.video = {};
+          expect(classifiedAsVideo(bid)).to.equal(true);
         });
 
-        it('should return false if bidRequest.mediaTypes.video.context is instream but size_id is not defined', function () {
-          expect(spec.isBidRequestValid({
-            mediaTypes: {
-              video: {
-                context: 'instream'
-              }
-            },
-            params: {
-              video: {}
-            }
-          })).is.equal(false);
+        it('Should return true and create a params.video object if one is not already present', function () {
+          createVideoBidderRequestNoVideo();
+          let bid = bidderRequest.bids[0]
+          expect(classifiedAsVideo(bid)).to.equal(true);
+          expect(bid.params.video).to.not.be.undefined;
         });
       });
     });