diff --git a/lib/GoogleSpreadsheet.js b/lib/GoogleSpreadsheet.js
index 28ff27f..ea463b7 100644
--- a/lib/GoogleSpreadsheet.js
+++ b/lib/GoogleSpreadsheet.js
@@ -72,11 +72,13 @@ class GoogleSpreadsheet {
   }
 
   // creds should be an object obtained by loading the json file google gives you
-  async useServiceAccountAuth(creds) {
+  // impersonateAs is an email of any user in the G Suite domain that has delegated domain-wide authority to the service account
+  async useServiceAccountAuth(creds, impersonateAs = null) {
     this.jwtClient = new JWT({
       email: creds.client_email,
       key: creds.private_key,
       scopes: GOOGLE_AUTH_SCOPES,
+      subject: impersonateAs
     });
     await this.renewJwtAuth();
   }