1 files changed, 1 insertions, 1 deletions

diff --git a/src/window.h b/src/window.h
index df7c23f824b..25c9686a9f0 100644
--- a/src/window.h
+++ b/src/window.h
@@ -88,7 +88,7 @@ struct cursor_pos
 struct window
   {
     /* This is for Lisp; the terminal code does not refer to it.  */
-    struct vectorlike_header header;
+    union vectorlike_header header;
 
     /* The frame this window is on.  */
     Lisp_Object frame;