diff --git a/RELEASE-NOTES.txt b/RELEASE-NOTES.txt
index 7081f6e..1d6cc74 100644
--- a/RELEASE-NOTES.txt
+++ b/RELEASE-NOTES.txt
@@ -29,6 +29,9 @@
 o VFS-621:  Add API VFS.setManager(FileSystemManager).
 o VFS-643:  VFS should not log at the INFO level.
 
+Known Problems:
+o VFS-645:  VfsClassLoaderTests fails on Java 9.
+
 
 Historical list of changes: http://commons.apache.org/proper/commons-vfs/changes-report.html