diff --git a/build.gradle b/build.gradle
index f8d75afb65..d92f97b073 100644
--- a/build.gradle
+++ b/build.gradle
@@ -256,6 +256,7 @@ test {
     jvmArgs += "-Xmx3072m"
     if (JavaVersion.current() > JavaVersion.VERSION_1_8) {
         jvmArgs += "--add-opens=java.base/java.io=ALL-UNNAMED"
+        // this needed to reflect access system env map.
         jvmArgs += "--add-opens=java.base/java.util=ALL-UNNAMED"
     }
     retry {
@@ -304,6 +305,7 @@ def setCommonTestConfig(Test task) {
     task.jvmArgs += "-Xmx3072m"
     if (JavaVersion.current() > JavaVersion.VERSION_1_8) {
         task.jvmArgs += "--add-opens=java.base/java.io=ALL-UNNAMED"
+        // this needed to reflect access system env map.
         task.jvmArgs += "--add-opens=java.base/java.util=ALL-UNNAMED"
     }
     task.retry {