diff --git a/packages/grpc-js/src/xds-bootstrap.ts b/packages/grpc-js/src/xds-bootstrap.ts
index 47e7679e..00e13d09 100644
--- a/packages/grpc-js/src/xds-bootstrap.ts
+++ b/packages/grpc-js/src/xds-bootstrap.ts
@@ -171,7 +171,7 @@ function validateNode(obj: any): Node {
     result.locality.region = obj.locality.region;
   }
   if ('zone' in obj.locality) {
-    if (typeof obj.locality.region !== 'string') {
+    if (typeof obj.locality.zone !== 'string') {
       throw new Error(
         `node.locality.zone field: expected string, got ${typeof obj.locality
           .zone}`