Exception running FXMark with JavaFX 9

[Felix Bembrick]

I am trying to port FXMark from Java 8 to Java 9 but encounter this
exception:

Caused by: java.lang.IllegalAccessError: class com.bembrick.fxmark.HUD (in
unnamed module @0x59223fd5) cannot access class
com.sun.javafx.perf.PerformanceTracker (in module javafx.graphics) because
module javafx.graphics does not export com.sun.javafx.perf to unnamed
module @0x59223fd5

How do I access PerformanceTracker in Java/JavaFX 9?

Thanks,

Felix