diff --git a/ChangeLog b/ChangeLog
index 658ddd95c..6d49a9f3d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2021-01-17  Werner Lemberg  <wl@gnu.org>
+
+	* src/tools/update-copyright-year: Fix single-year entry handling.
+
 2021-01-16  Alexei Podtelezhnikov  <apodtele@gmail.com>
 
 	* builds/unix/unixddef.mk: Remove the second DEVEL_DIR definition.
diff --git a/src/tools/update-copyright-year b/src/tools/update-copyright-year
index 504f99c30..fdd270ac4 100755
--- a/src/tools/update-copyright-year
+++ b/src/tools/update-copyright-year
@@ -28,20 +28,20 @@ eval '(exit $?0)' && eval 'exec perl -wS -i "$0" ${1+"$@"}'
 #
 # or
 #
-#   /* Copyright 2000,  2001, 2004-2007 by    */
-#   /* foobar                                 */
+#   /* Copyright (c) 2000,  2001, 2004-2007 by    */
+#   /* foobar                                     */
 #
 # and replaces them uniformly with
 #
-#   Copyright 2000-2015
+#   Copyright (C) 2000-2021
 #   foobar
 #
 # and
 #
-#   /* Copyright 2000-2015 by                 */
-#   /* foobar                                 */
+#   /* Copyright (C) 2000-2021 by                 */
+#   /* foobar                                     */
 #
-# (assuming that the current year is 2015).  As can be seen, the line length
+# (assuming that the current year is 2021).  As can be seen, the line length
 # is retained if there is non-whitespace after the word `by' on the same
 # line.
 
@@ -80,11 +80,11 @@ while (<>)
       {
         # Fill line to the same length (if appropriate); we skip the middle
         # part but insert `(C)', three spaces, and `-'.
-        my $space = length($+{space1}) - 1
-                    + length($+{middle}) - 1
-                    + length($+{space2}) - 1
+        my $space = length($+{space1})
+                    + length($+{middle})
+                    + length($+{space2})
                     + length($+{space3})
-                    - (length("(C)") + 1);
+                    - (length("(C)") + 3 + 1);
 
         print "$+{begin}";
         print "Copyright\ (C)\ $+{first}-$year\ by";
@@ -107,11 +107,11 @@ while (<>)
       }
       {
         # Fill line to the same length (if appropriate); we insert three
-        # spaces, a `-', and the current year.
-        my $space = length($+{space1}) - 1
-                    + length($+{space2}) - 1
+        # spaces, the string `(C)', a `-', and the current year.
+        my $space = length($+{space1})
+                    + length($+{space2})
                     + length($+{space3})
-                    - (length($year) + 1);
+                    - (length($year) + length("(C)") + 3 + 1);
 
         print "$+{begin}";
         print "Copyright\ (C)\ $+{first}-$year\ by";