1 files changed, 5 insertions, 0 deletions

diff --git a/src/buffer.c b/src/buffer.c
index e1caaac5f89..baa977ab853 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3679,6 +3679,10 @@ modify_overlay (buf, start, end)
   /* If multiple windows show this buffer, we must do other windows.  */
   else if (buffer_shared > 1)
     windows_or_buffers_changed = 1;
+  /* If we modify an overlay at the end of the buffer, we cannot
+     be sure that window end is still valid.  */
+  else if (end >= ZV && start <= ZV)
+    windows_or_buffers_changed = 1;
 
   ++BUF_OVERLAY_MODIFF (buf);
 }
@@ -4120,6 +4124,7 @@ DEFUN ("overlay-put", Foverlay_put, Soverlay_put, 3, 3, 0,
               == OVERLAY_POSITION (OVERLAY_END (overlay))))
         Fdelete_overlay (overlay);
     }
+
   return value;
 }