diff -r 52cb065aa916 -r 07edf1952ab1 src/Pure/Thy/file_format.scala
--- a/src/Pure/Thy/file_format.scala	Wed Nov 18 15:47:53 2020 +0100
+++ b/src/Pure/Thy/file_format.scala	Wed Nov 18 15:52:12 2020 +0100
@@ -88,7 +88,7 @@
     } yield s
   }
 
-  def make_preview(snapshot: Document.Snapshot): Option[Present.Preview] = None
+  def make_preview(snapshot: Document.Snapshot): Option[Presentation.Preview] = None
 
 
   /* PIDE session agent */