diff --git a/src/config.js b/src/config.js
index 8484b87b77c..264c654e596 100644
--- a/src/config.js
+++ b/src/config.js
@@ -17,6 +17,7 @@ import find from 'core-js/library/fn/array/find.js';
 import includes from 'core-js/library/fn/array/includes.js';
 import Set from 'core-js/library/fn/set.js';
 import { parseQS } from './url.js';
+import { mergeDeep } from './utils.js';
 
 const from = require('core-js/library/fn/array/from.js');
 const utils = require('./utils.js');
@@ -255,7 +256,7 @@ export function newConfig() {
           memo[topic] = currBidderConfig[topic];
         } else {
           if (utils.isPlainObject(currBidderConfig[topic])) {
-            memo[topic] = Object.assign({}, config[topic], currBidderConfig[topic]);
+            memo[topic] = mergeDeep({}, config[topic], currBidderConfig[topic]);
           } else {
             memo[topic] = currBidderConfig[topic];
           }
diff --git a/src/utils.js b/src/utils.js
index fbc0e76d167..283648f217a 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -1348,3 +1348,25 @@ export function compareOn(property) {
     return 0;
   }
 }
+
+export function isObject(item) {
+  return (item && typeof item === 'object' && !Array.isArray(item));
+}
+
+export function mergeDeep(target, ...sources) {
+  if (!sources.length) return target;
+  const source = sources.shift();
+
+  if (isObject(target) && isObject(source)) {
+    for (const key in source) {
+      if (isObject(source[key])) {
+        if (!target[key]) Object.assign(target, { [key]: {} });
+        mergeDeep(target[key], source[key]);
+      } else {
+        Object.assign(target, { [key]: source[key] });
+      }
+    }
+  }
+
+  return mergeDeep(target, ...sources);
+}
diff --git a/test/spec/unit/core/adapterManager_spec.js b/test/spec/unit/core/adapterManager_spec.js
index 566ebe2e400..e10017f57f7 100644
--- a/test/spec/unit/core/adapterManager_spec.js
+++ b/test/spec/unit/core/adapterManager_spec.js
@@ -175,7 +175,7 @@ describe('adapterManager tests', function () {
         buildRequests: {
           data: 1
         },
-        test1: { speedy: true },
+        test1: { speedy: true, fun: { test: true } },
         interpretResponse: 'baseInterpret',
         afterInterpretResponse: 'anotherBaseInterpret'
       });
@@ -212,7 +212,7 @@ describe('adapterManager tests', function () {
               data: 1,
               test: 2
             },
-            { fun: { safe: true, cheap: false }, speedy: true },
+            { fun: { safe: true, cheap: false, test: true }, speedy: true },
             { amazing: true },
             'appnexusInterpret',
             'anotherBaseInterpret'
@@ -221,14 +221,14 @@ describe('adapterManager tests', function () {
             {
               data: 1
             },
-            { speedy: true },
+            { fun: { test: true }, speedy: true },
             undefined,
             'baseInterpret',
             'anotherBaseInterpret'
           ],
           'rubicon': [
             'rubiconBuild',
-            { speedy: true },
+            { fun: { test: true }, speedy: true },
             { amazing: true },
             null,
             'anotherBaseInterpret'