diff --git a/modules/admixerBidAdapter.js b/modules/admixerBidAdapter.js
index 5cf3cc44cdd..e979bd07b51 100644
--- a/modules/admixerBidAdapter.js
+++ b/modules/admixerBidAdapter.js
@@ -24,7 +24,7 @@ export const spec = {
    */
   isBidRequestValid: function (bid) {
     return bid.bidder === 'rtbstack'
-      ? !!bid.params.endpointId
+      ? !!bid.params.tagId
       : !!bid.params.zone;
   },
   /**
diff --git a/modules/admixerBidAdapter.md b/modules/admixerBidAdapter.md
index abaebfce065..097e7feb95e 100644
--- a/modules/admixerBidAdapter.md
+++ b/modules/admixerBidAdapter.md
@@ -61,7 +61,7 @@ Please use ```admixer``` as the bidder code.
                    {
                        bidder: "rtbstack",
                        params: {
-                           endpointId: 41512
+                           tagId: 41512
                        }
                    }
                ]
@@ -72,7 +72,7 @@ Please use ```admixer``` as the bidder code.
                    {
                        bidder: "rtbstack",
                        params: {
-                           endpointId: 41512
+                           tagId: 41512
                        }
                    }
                ]
@@ -84,7 +84,7 @@ Please use ```admixer``` as the bidder code.
                    {
                        bidder: "rtbstack",
                        params: {
-                           endpointId: 41512
+                           tagId: 41512
                        }
                    }
                ]
diff --git a/test/spec/modules/admixerBidAdapter_spec.js b/test/spec/modules/admixerBidAdapter_spec.js
index cf9398c6119..e53457e03c4 100644
--- a/test/spec/modules/admixerBidAdapter_spec.js
+++ b/test/spec/modules/admixerBidAdapter_spec.js
@@ -40,7 +40,7 @@ describe('AdmixerAdapter', function () {
     let rtbBid = {
       bidder: RTB_BIDDER_CODE,
       params: {
-        endpointId: ENDPOINT_ID,
+        tagId: ENDPOINT_ID,
       },
       adUnitCode: 'adunit-code',
       sizes: [
@@ -133,7 +133,7 @@ describe('AdmixerAdapter', function () {
         {
           bidder: bidder,
           params: bidder === 'rtbstack' ? {
-            endpointId: ENDPOINT_ID
+            tagId: ENDPOINT_ID
           } : {
             zone: ZONE_ID,
           },