diff --git a/build.gradle b/build.gradle
index 8d83a2a..5c6ae6b 100644
--- a/build.gradle
+++ b/build.gradle
@@ -145,7 +145,7 @@ githubRelease.doFirst {
 }
 
 tasks.withType(Test).configureEach { task ->
-    if (JavaVersion.current().compareTo(JavaVersion.VERSION_17) > 0) {
+    if (JavaVersion.current().compareTo(JavaVersion.VERSION_17) > 0 && JavaVersion.current().compareTo(JavaVersion.VERSION_21) < 0) {
         def policyFile = file("${projectDir}/src/main/plugin-metadata/plugin-security.policy").absolutePath
         task.jvmArgs += [
             "--add-opens", "java.base/java.lang=ALL-UNNAMED",