diff --git a/src/utils/api-request.ts b/src/utils/api-request.ts
index 4b7170ed68..dbf5d7e2c6 100644
--- a/src/utils/api-request.ts
+++ b/src/utils/api-request.ts
@@ -1112,6 +1112,15 @@ export class AuthorizedHttp2Client extends Http2Client {
       const authHeader = 'Authorization';
       requestCopy.headers[authHeader] = `Bearer ${token}`;
 
+      let quotaProjectId: string | undefined;
+      if (this.app.options.credential instanceof ApplicationDefaultCredential){
+        quotaProjectId = this.app.options.credential.getQuotaProjectId();
+      }
+      quotaProjectId = process.env.GOOGLE_CLOUD_QUOTA_PROJECT || undefined;
+      if (!requestCopy.headers['x-goog-user-project'] && validator.isNonEmptyString(quotaProjectId)) {
+        requestCopy.headers['x-goog-user-project'] = quotaProjectId;
+      }
+
       return super.send(requestCopy);
     });
   }