diff --git a/src/ChangeLog b/src/ChangeLog
index 01163fc525933e5b070e62c171c4b2c1c0dae691..676d03cb59dc355a7abbb073e148390e832d12e4 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,12 @@
+2020-08-17  Per Cederqvist  <ceder@lysator.liu.se>
+
+	Emacs 27.1 compatibility.
+	* view-text.el (lyskom-subtract-one-day): Keep any sub-second time
+	elements unchanged, so that we return a valid time format.  Emacs
+	27.1 expects it to be on the (HI LO US PS) form, and decode-time
+	will raise an error if it is on the (HI LO nil) form that
+	lyskom-subtract-one-day previously returned.
+
 2019-08-08  Per Cederqvist  <cederp@opera.com>
 
 	Insert links to jskom when an image cannot be displayed.
diff --git a/src/view-text.el b/src/view-text.el
index e3de9cfdbaf92dbf92c0684be058637ea43deb51..da8bdaeb948252211da9d1ba189e20663a07206e 100644
--- a/src/view-text.el
+++ b/src/view-text.el
@@ -716,7 +716,7 @@ blocking-do."
         (setq high-x (1- high-x)
               low-x (+ low-x 65536)))
     (setq low-x (- low-x 20864))
-    (list high-x low-x nil)))
+    (cons high-x (cons low-x (cdr (cdr x))))))
 
 (defun lyskom-calculate-day-diff (time)
   (let* ((now (current-time))