diff --git a/src/targeting.js b/src/targeting.js
index a140c952230..7d587e8ac97 100644
--- a/src/targeting.js
+++ b/src/targeting.js
@@ -18,6 +18,10 @@ var pbTargetingKeys = [];
 const MAX_DFP_KEYLENGTH = 20;
 const TTL_BUFFER = 1000;
 
+const CFG_ALLOW_TARGETING_KEYS = `targetingControls.allowTargetingKeys`;
+const CFG_ADD_TARGETING_KEYS = `targetingControls.addTargetingKeys`;
+const TARGETING_KEY_CONFIGURATION_ERROR_MSG = `Only one of "${CFG_ALLOW_TARGETING_KEYS}" or "${CFG_ADD_TARGETING_KEYS}" can be set`;
+
 export const TARGETING_KEYS = Object.keys(CONSTANTS.TARGETING_KEYS).map(
   key => CONSTANTS.TARGETING_KEYS[key]
 );
@@ -261,7 +265,17 @@ export function newTargeting(auctionManager) {
     });
 
     const defaultKeys = Object.keys(Object.assign({}, CONSTANTS.DEFAULT_TARGETING_KEYS, CONSTANTS.NATIVE_KEYS));
-    const allowedKeys = config.getConfig('targetingControls.allowTargetingKeys') || defaultKeys;
+    let allowedKeys = config.getConfig(CFG_ALLOW_TARGETING_KEYS);
+    const addedKeys = config.getConfig(CFG_ADD_TARGETING_KEYS);
+
+    if (addedKeys != null && allowedKeys != null) {
+      throw new Error(TARGETING_KEY_CONFIGURATION_ERROR_MSG);
+    } else if (addedKeys != null) {
+      allowedKeys = defaultKeys.concat(addedKeys);
+    } else {
+      allowedKeys = allowedKeys || defaultKeys;
+    }
+
     if (Array.isArray(allowedKeys) && allowedKeys.length > 0) {
       targeting = getAllowedTargetingKeyValues(targeting, allowedKeys);
     }
@@ -284,6 +298,13 @@ export function newTargeting(auctionManager) {
     return targeting;
   };
 
+  // warn about conflicting configuration
+  config.getConfig('targetingControls', function (config) {
+    if (deepAccess(config, CFG_ALLOW_TARGETING_KEYS) != null && deepAccess(config, CFG_ADD_TARGETING_KEYS) != null) {
+      logError(TARGETING_KEY_CONFIGURATION_ERROR_MSG);
+    }
+  });
+
   // create an encoded string variant based on the keypairs of the provided object
   //  - note this will encode the characters between the keys (ie = and &)
   function convertKeysToQueryForm(keyMap) {
diff --git a/test/spec/unit/core/targeting_spec.js b/test/spec/unit/core/targeting_spec.js
index 1064d7c0f7d..abef2acd154 100644
--- a/test/spec/unit/core/targeting_spec.js
+++ b/test/spec/unit/core/targeting_spec.js
@@ -5,6 +5,7 @@ import { createBidReceived } from 'test/fixtures/fixtures.js';
 import CONSTANTS from 'src/constants.json';
 import { auctionManager } from 'src/auctionManager.js';
 import * as utils from 'src/utils.js';
+import {deepClone} from 'src/utils.js';
 
 const bid1 = {
   'bidderCode': 'rubicon',
@@ -501,6 +502,77 @@ describe('targeting tests', function () {
       });
     });
 
+    describe('targetingControls.addTargetingKeys', function () {
+      let winningBid = null;
+
+      beforeEach(function () {
+        bidsReceived = [bid1, bid2, nativeBid1, nativeBid2].map(deepClone);
+        bidsReceived.forEach((bid) => {
+          bid.adserverTargeting[CONSTANTS.TARGETING_KEYS.SOURCE] = 'test-source';
+          bid.adUnitCode = 'adunit';
+          if (winningBid == null || bid.cpm > winningBid.cpm) {
+            winningBid = bid;
+          }
+        });
+        enableSendAllBids = true;
+      });
+
+      const expandKey = function (key) {
+        const keys = new Set();
+        if (winningBid.adserverTargeting[key] != null) {
+          keys.add(key);
+        }
+        bidsReceived
+          .filter((bid) => bid.adserverTargeting[key] != null)
+          .map((bid) => bid.bidderCode)
+          .forEach((code) => keys.add(`${key}_${code}`.substr(0, 20)));
+        return new Array(...keys);
+      }
+
+      const targetingResult = function () {
+        return targetingInstance.getAllTargeting(['adunit'])['adunit'];
+      }
+
+      it('should include added keys', function () {
+        config.setConfig({
+          targetingControls: {
+            addTargetingKeys: ['SOURCE']
+          }
+        });
+        expect(targetingResult()).to.include.all.keys(...expandKey(CONSTANTS.TARGETING_KEYS.SOURCE));
+      });
+
+      it('should keep default and native keys', function() {
+        config.setConfig({
+          targetingControls: {
+            addTargetingKeys: ['SOURCE']
+          }
+        });
+        const defaultKeys = new Set(Object.values(CONSTANTS.DEFAULT_TARGETING_KEYS));
+        Object.values(CONSTANTS.NATIVE_KEYS).forEach((k) => defaultKeys.add(k));
+
+        const expectedKeys = new Set();
+        bidsReceived
+          .map((bid) => Object.keys(bid.adserverTargeting))
+          .reduce((left, right) => left.concat(right), [])
+          .filter((key) => defaultKeys.has(key))
+          .map(expandKey)
+          .reduce((left, right) => left.concat(right), [])
+          .forEach((k) => expectedKeys.add(k));
+        expect(targetingResult()).to.include.all.keys(...expectedKeys);
+      });
+
+      it('should not be allowed together with allowTargetingKeys', function () {
+        config.setConfig({
+          targetingControls: {
+            allowTargetingKeys: [CONSTANTS.TARGETING_KEYS.BIDDER],
+            addTargetingKeys: [CONSTANTS.TARGETING_KEYS.SOURCE]
+          }
+        });
+        expect(targetingResult).to.throw();
+      });
+    });
+
     describe('targetingControls.allowSendAllBidsTargetingKeys', function () {
       let bid4;