Gradle refresh fails under JDK7 since updating to 2017.2

Dear all,

I have updated to version 2017.2 of IntelliJ today and since then gradle refresh refuses to work. I get the following error message:

Error:Cause: com/android/builder/model/NativeAndroidProject has been compiled by a more recent version of the Java Runtime (class file version 52.0), this version of the Java Runtime only recognizes class file versions up to 51.0

My project is a regular J2EE-project, it has nothing to do with android at all.

Now, while it is possible to "fix" this issue by setting the gradle JVM to a Java 8 installation, this does not really help as my project is limited to java 7. Using Java 8 with gradle causes it to mess up my project settings everytime I refresh. 

Does anybody know a proper solution for this?

Thanks in advance!

Best regards,

Felix