the gradle-wrapper.jar is created by the gradle instance used to create the wrapper scripts directly. It’s not downloaded from anywhere. Usually this just works fine. To ensure you get the gradle-wrapper.jar of 1.9 you would need to run the wrapper task using gradle 1.9
That makes sense. I use a multi module project and executed the wrapper task from rootProject where the gradle-wrapper version 1.8 is set. After I switched to 1.9 in rootProject the gradle-wrapper.jar gets updated.