diff --git a/modules/tripleliftBidAdapter.js b/modules/tripleliftBidAdapter.js
index 45931bce27e..df00495b88b 100644
--- a/modules/tripleliftBidAdapter.js
+++ b/modules/tripleliftBidAdapter.js
@@ -9,7 +9,7 @@ const BIDDER_CODE = 'triplelift';
 const STR_ENDPOINT = 'https://tlx.3lift.com/header/auction?';
 const BANNER_TIME_TO_LIVE = 300;
 const VIDEO_TIME_TO_LIVE = 3600;
-let gdprApplies = true;
+let gdprApplies = null;
 let consentString = null;
 export const storage = getStorageManager({bidderCode: BIDDER_CODE});
 
@@ -40,8 +40,12 @@ export const tripleliftAdapterSpec = {
     if (bidderRequest && bidderRequest.gdprConsent) {
       if (typeof bidderRequest.gdprConsent.gdprApplies !== 'undefined') {
         gdprApplies = bidderRequest.gdprConsent.gdprApplies;
-        tlCall = tryAppendQueryString(tlCall, 'gdpr', gdprApplies.toString());
+      } else {
+        gdprApplies = true;
       }
+
+      tlCall = tryAppendQueryString(tlCall, 'gdpr', gdprApplies.toString());
+
       if (typeof bidderRequest.gdprConsent.consentString !== 'undefined') {
         consentString = bidderRequest.gdprConsent.consentString;
         tlCall = tryAppendQueryString(tlCall, 'cmp_cs', consentString);
@@ -87,7 +91,7 @@ export const tripleliftAdapterSpec = {
       syncEndpoint = tryAppendQueryString(syncEndpoint, 'src', 'prebid');
     }
 
-    if (consentString !== null) {
+    if (consentString !== null || gdprApplies) {
       syncEndpoint = tryAppendQueryString(syncEndpoint, 'gdpr', gdprApplies);
       syncEndpoint = tryAppendQueryString(syncEndpoint, 'cmp_cs', consentString);
     }