diff --git a/git_hooks/Makefile b/git_hooks/Makefile
new file mode 100644
index 000000000..d35b8e50e
--- /dev/null
+++ b/git_hooks/Makefile
@@ -0,0 +1,16 @@
+#---------------------------------------------------------------------------#
+# vim: ts=8 sw=8 noexpandtab
+#---------------------------------------------------------------------------#
+#
+# A makefile for the update_copyright program.
+#
+# This Makefile is designed for manual operation by Mercury developers;
+# it is *not* designed to be invoked by any action in any other Makefile
+# or Mmakefile, in any other part of that workspace.
+#
+
+update_copyright:   update_copyright.m
+	mmc --mercury-linkage static update_copyright.m
+
+clean:
+	git clean -fx 'update_copyright.*' 'update_copyright_init.*'
diff --git a/git_hooks/update_copyright.m b/git_hooks/update_copyright.m
index 229076c23..a63eed04b 100644
--- a/git_hooks/update_copyright.m
+++ b/git_hooks/update_copyright.m
@@ -208,9 +208,9 @@ read_lines_loop(InputStream, Options, CurrentYear,
             !.ModState = unmodified,
             parse_copyright_line(Options, Line, Prefix, Ranges0, Suffix)
         then
-            % We could normalise ranges here.
-            sort(Ranges0, Ranges1),
-            ( if add_to_ranges(CurrentYear, Ranges1, Ranges) then
+            list.sort(Ranges0, Ranges1),
+            merge_adjacent_ranges_if_possible(Ranges1, Ranges2),
+            ( if add_to_ranges(CurrentYear, Ranges2, Ranges) then
                 make_copyright_line(Prefix, Ranges, Suffix, NewLine),
                 !:RevLines = [NewLine | !.RevLines],
                 !:ModState = found_modified
@@ -289,6 +289,13 @@ parse_ranges(Str, Ranges) :-
     Words = string.words_separator(is_whitespace_or_comma, Str),
     list.map(parse_range, Words, Ranges).
 
+:- pred is_whitespace_or_comma(char::in) is semidet.
+
+is_whitespace_or_comma(C) :-
+    ( char.is_whitespace(C)
+    ; C = (',')
+    ).
+
 :- pred parse_range(string::in, year_range::out) is semidet.
 
 parse_range(Str, Range) :-
@@ -305,11 +312,27 @@ parse_range(Str, Range) :-
         Range = years(N1, N2)
     ).
 
-:- pred is_whitespace_or_comma(char::in) is semidet.
+:- pred merge_adjacent_ranges_if_possible(
+    list(year_range)::in, list(year_range)::out) is det.
 
-is_whitespace_or_comma(C) :-
-    ( char.is_whitespace(C)
-    ; C = (',')
+merge_adjacent_ranges_if_possible(Ranges0, Ranges) :-
+    (
+        ( Ranges0 = []
+        ; Ranges0 = [_]
+        ),
+        Ranges = Ranges0
+    ;
+        Ranges0 = [Range1, Range2 | Ranges3plus],
+        Range1 = years(RangeLo1, RangeHi1),
+        Range2 = years(RangeLo2, RangeHi2),
+        ( if RangeLo2 =< RangeHi1 + 1 then
+            Range12 = years(RangeLo1, RangeHi2),
+            merge_adjacent_ranges_if_possible([Range12 | Ranges3plus], Ranges)
+        else
+            merge_adjacent_ranges_if_possible([Range2 | Ranges3plus],
+                TailRanges),
+            Ranges = [Range1 | TailRanges]
+        )
     ).
 
 :- pred add_to_ranges(int::in, list(year_range)::in, list(year_range)::out)
diff --git a/git_hooks/update_copyright.pre-commit b/git_hooks/update_copyright.pre-commit
index 5b6bcf161..e1d965c34 100755
--- a/git_hooks/update_copyright.pre-commit
+++ b/git_hooks/update_copyright.pre-commit
@@ -1,26 +1,46 @@
 #!/usr/bin/env bash
 #
-# You can copy/symlink this script to .git/hooks/pre-commit.
-# It will update the Copyright lines of all files that are going to be
-# modified in the commit, before the commit is made.
+# This script is designed to update the Copyright lines of all files
+# that are going to be modified in the commit in a workspace,
+# before the commit is made.
 #
-# You need to compile the update_copyright.m program:
-#   mmc --mercury-linkage static update_copyright.m
+# If ${ws} is the pathname of a workspace, then you enable this script
+# for that workspace by
 #
-# You can clean the intermediate files with:
-#   git clean -fx 'update_copyright.*' 'update_copyright_init.*'
+# - compiling update_copyright.m to an executable, and
+# - copying or symlinking this script to ${ws}/.git/hooks/pre-commit.
 #
+# The first step can be done by the command
+#
+#   make update_copyright
+#
+# The unneeded intermediate files from the first step can cleaned up
+# by the command
+#
+#   make clean
+#
+# By default, this script requires the executable git_hooks/update_copyright
+# to be present in the workspace. You can avoid having a duplicate copy
+# of that executable in every workspace by
+#
+# - putting that executable in some central location, and
+# - setting the environment variable UPDATE_MERCURY_COPYRIGHT
+#   to invoke that executable.
+#
+
 set -e
 
 rootdir=$( git rev-parse --show-toplevel )
-update_copyright="$rootdir/git_hooks/update_copyright"
-
-# Only continue if the update_copyright program has been compiled.
-if test ! -x "$update_copyright"
+if test "${UPDATE_MERCURY_COPYRIGHT}" != ""
 then
-    exit
+    update_copyright="${UPDATE_MERCURY_COPYRIGHT}"
+else
+    update_copyright="${rootdir}/git_hooks/update_copyright"
 fi
 
+# Continue only if the update_copyright program is available.
+command -v "${update_copyright}" > /dev/null || exit 0
+
 # Find changed files for this commit.
 changed_files=($( git diff --name-only --cached --diff-filter=ACMR ))
 update_files=()
@@ -28,7 +48,7 @@ unknown_files=()
 
 for file in "${changed_files[@]}"
 do
-    case $file in
+    case ${file} in
         *.[mchly] | *.in | *.java | *Mmake*)
             update_files+=( "$file" )
             ;;
@@ -47,5 +67,5 @@ fi
 if test "${#update_files}" -gt 0
 then
     # Accept both "Mercury team" and "Mercury Team".
-    exec "$update_copyright" --suffix ' Mercury ' -- "${update_files[@]}"
+    exec "${update_copyright}" --suffix ' Mercury ' -- "${update_files[@]}"
 fi