diff --git a/modules/pubmaticBidAdapter.js b/modules/pubmaticBidAdapter.js
index 9ab5984860b..42c05f765bc 100644
--- a/modules/pubmaticBidAdapter.js
+++ b/modules/pubmaticBidAdapter.js
@@ -1112,6 +1112,9 @@ export const spec = {
       payload.device = Object.assign(payload.device, config.getConfig('device'));
     }
 
+    // update device.language to ISO-639-1-alpha-2 (2 character language)
+    payload.device.language = payload.device.language && payload.device.language.split('-')[0];
+
     // passing transactionId in source.tid
     deepSetValue(payload, 'source.tid', conf.transactionId);
 
diff --git a/test/spec/modules/pubmaticBidAdapter_spec.js b/test/spec/modules/pubmaticBidAdapter_spec.js
index e8bedc851c7..6e65e725024 100644
--- a/test/spec/modules/pubmaticBidAdapter_spec.js
+++ b/test/spec/modules/pubmaticBidAdapter_spec.js
@@ -1141,7 +1141,7 @@ describe('PubMatic adapter', function () {
         expect(data.device.dnt).to.equal((navigator.doNotTrack == 'yes' || navigator.doNotTrack == '1' || navigator.msDoNotTrack == '1') ? 1 : 0);
         expect(data.device.h).to.equal(screen.height);
         expect(data.device.w).to.equal(screen.width);
-        expect(data.device.language).to.equal(navigator.language);
+        expect(data.device.language).to.equal(navigator.language.split('-')[0]);
         expect(data.device.newkey).to.equal('new-device-data');// additional data from config
         sandbox.restore();
       });