diff --git a/libraries/appnexusKeywords/anKeywords.js b/libraries/appnexusKeywords/anKeywords.js
index 6be287365cb..337f76c71a3 100644
--- a/libraries/appnexusKeywords/anKeywords.js
+++ b/libraries/appnexusKeywords/anKeywords.js
@@ -3,8 +3,8 @@ import {getAllOrtbKeywords} from '../keywords/keywords.js';
 import {CLIENT_SECTIONS} from '../../src/fpd/oneClient.js';
 
 const ORTB_SEGTAX_KEY_MAP = {
-  526: '1plusx',
-  527: '1plusx',
+  526: '1plusX',
+  527: '1plusX',
   541: 'captify_segments',
   540: 'perid'
 };
diff --git a/test/spec/modules/appnexusBidAdapter_spec.js b/test/spec/modules/appnexusBidAdapter_spec.js
index d54944f2092..54e2d60bba0 100644
--- a/test/spec/modules/appnexusBidAdapter_spec.js
+++ b/test/spec/modules/appnexusBidAdapter_spec.js
@@ -840,7 +840,7 @@ describe('AppNexusAdapter', function () {
       expectKeywords(payload.keywords, [{
         'key': 'drill'
       }, {
-        'key': '1plusx',
+        'key': '1plusX',
         'value': ['cat', 'dog']
       }, {
         'key': 'perid',