diff --git a/modules/dasBidAdapter.js b/modules/dasBidAdapter.js
index 557ebaceed8..1327ec9f1e4 100644
--- a/modules/dasBidAdapter.js
+++ b/modules/dasBidAdapter.js
@@ -248,6 +248,13 @@ function buildOpenRTBRequest(bidRequests, bidderRequest) {
     request.ext.adbeta = customParams.adbeta;
   }
 
+  // AdShield anti-adblock recovery signal (set by dlApi as customParams.asd, like adbeta).
+  // Sent as a plain ext field (not a key-value) so das-bidder serves only
+  // adblock-compatible demand (adblock_compability == 2).
+  if (customParams.asd) {
+    request.ext.asd = customParams.asd;
+  }
+
   if (bidderRequest.device) {
     request.device = bidderRequest.device;
   }
diff --git a/test/spec/modules/dasBidAdapter_spec.js b/test/spec/modules/dasBidAdapter_spec.js
index 271a1afb9f0..d8252171945 100644
--- a/test/spec/modules/dasBidAdapter_spec.js
+++ b/test/spec/modules/dasBidAdapter_spec.js
@@ -179,6 +179,31 @@ describe('dasBidAdapter', function () {
       expect(payload.imp[0].banner.format[0]).to.deep.equal({ w: 300, h: 250 });
     });
 
+    it('should route customParams.asd into ext.asd for AdShield recovery', function () {
+      const asdBidRequests = [{
+        ...bidRequests[0],
+        params: {
+          ...bidRequests[0].params,
+          customParams: { asd: 1 }
+        }
+      }];
+
+      const request = spec.buildRequests(asdBidRequests, bidderRequest);
+      const params = new URLSearchParams(request.url.split('?')[1]);
+      const payload = JSON.parse(decodeURIComponent(params.get('data')));
+
+      expect(payload.ext.asd).to.equal(1);
+      expect(payload.ext.keyvalues.asd).to.be.undefined;
+    });
+
+    it('should not set ext.asd without customParams.asd', function () {
+      const request = spec.buildRequests(bidRequests, bidderRequest);
+      const params = new URLSearchParams(request.url.split('?')[1]);
+      const payload = JSON.parse(decodeURIComponent(params.get('data')));
+
+      expect(payload.ext.asd).to.be.undefined;
+    });
+
     it('should use GET method when URL is under 8192 characters', function () {
       const request = spec.buildRequests(bidRequests, bidderRequest);
       expect(request.method).to.equal('GET');