diff --git a/xds/internal/balancer/edsbalancer/eds_testutil_test.go b/xds/internal/balancer/edsbalancer/eds_testutil_test.go
index 8622d2a8d681..c8be545d8b50 100644
--- a/xds/internal/balancer/edsbalancer/eds_testutil_test.go
+++ b/xds/internal/balancer/edsbalancer/eds_testutil_test.go
@@ -1,3 +1,5 @@
+// +build go1.12
+
 /*
  * Copyright 2020 gRPC authors.
  *