diff --git a/make/autoconf/flags-cflags.m4 b/make/autoconf/flags-cflags.m4
index 76724235ec4..25f79c4bc7b 100644
--- a/make/autoconf/flags-cflags.m4
+++ b/make/autoconf/flags-cflags.m4
@@ -159,6 +159,7 @@ AC_DEFUN([FLAGS_SETUP_WARNINGS],
 
     clang)
       DISABLE_WARNING_PREFIX="-Wno-"
+      BUILD_CC_DISABLE_WARNING_PREFIX="-Wno-"
       CFLAGS_WARNINGS_ARE_ERRORS="-Werror"
 
       # Additional warnings that are not activated by -Wall and -Wextra
diff --git a/test/jdk/java/io/FileOutputStream/OpenNUL.java b/test/jdk/java/io/FileOutputStream/OpenNUL.java
index dc14db070a4..53a84504e13 100644
--- a/test/jdk/java/io/FileOutputStream/OpenNUL.java
+++ b/test/jdk/java/io/FileOutputStream/OpenNUL.java
@@ -26,7 +26,9 @@
  * @bug 8285445
  * @requires (os.family == "windows")
  * @summary Verify behavior of opening "NUL:" with ADS enabled and disabled.
+ * @run main/othervm OpenNUL
  * @run main/othervm -Djdk.io.File.enableADS OpenNUL
+ * @run main/othervm -Djdk.io.File.enableADS=FalsE OpenNUL
  * @run main/othervm -Djdk.io.File.enableADS=true OpenNUL
  */
 
@@ -36,7 +38,7 @@ import java.io.IOException;
 
 public class OpenNUL {
     public static void main(String args[]) throws IOException {
-        String enableADS = System.getProperty("jdk.io.File.enableADS");
+        String enableADS = System.getProperty("jdk.io.File.enableADS", "true");
         boolean fails = enableADS.equalsIgnoreCase(Boolean.FALSE.toString());
 
         FileOutputStream fos;