--- old/src/java.base/share/classes/java/nio/file/Path.java	2017-04-22 21:31:17.757175404 +0200
+++ new/src/java.base/share/classes/java/nio/file/Path.java	2017-04-22 21:31:17.680176732 +0200
@@ -652,7 +652,8 @@
      *          if this {@code Path} is not associated with the default provider
      */
     default File toFile() {
-        if (getFileSystem() == FileSystems.getDefault()) {
+        if (getFileSystem() == FileSystems.getBuiltin() ||
+            getFileSystem() == FileSystems.getDefault()) {
             return new File(toString());
         } else {
             throw new UnsupportedOperationException("Path not associated with "