src/java.base/share/classes/java/lang/reflect/Constructor.java

*** 179,188 ****
--- 179,194 ----
       */
      @Override
      @CallerSensitive
      public void setAccessible(boolean flag) {
          AccessibleObject.checkPermission();
+ 
+         if (clazz.isValue()) {
+             throw new InaccessibleObjectException(
+                 "Unable to make a value class constructor \"" + this + "\" accessible");
+         }
+ 
          if (flag) {
              checkCanSetAccessible(Reflection.getCallerClass());
          }
          setAccessible0(flag);
      }
*** 472,481 ****
--- 478,492 ----
      @ForceInline // to ensure Reflection.getCallerClass optimization
      public T newInstance(Object ... initargs)
          throws InstantiationException, IllegalAccessException,
                 IllegalArgumentException, InvocationTargetException
      {
+         if (clazz.isValue()) {
+             throw new IllegalAccessException(
+                 "cannot create new instance of value class " + clazz.getName());
+         }
+ 
          if (!override) {
              Class<?> caller = Reflection.getCallerClass();
              checkAccess(caller, clazz, clazz, modifiers);
          }
          if ((clazz.getModifiers() & Modifier.ENUM) != 0)