diff --git a/.gitignore b/.gitignore
index aebe7c0908..188bd1c3de 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,7 +83,6 @@
 /git-init-db
 /git-interpret-trailers
 /git-instaweb
-/git-legacy-stash
 /git-log
 /git-ls-files
 /git-ls-remote
diff --git a/Documentation/config/stash.txt b/Documentation/config/stash.txt
index abc7ef4a3a..00eb35434e 100644
--- a/Documentation/config/stash.txt
+++ b/Documentation/config/stash.txt
@@ -1,17 +1,9 @@
 stash.useBuiltin::
-       Set to `false` to use the legacy shell script implementation of
-       linkgit:git-stash[1]. Is `true` by default, which means use
-       the built-in rewrite of it in C.
-+
-The C rewrite is first included with Git version 2.22 (and Git for Windows
-version 2.19). This option serves as an escape hatch to re-enable the
-legacy version in case any bugs are found in the rewrite. This option and
-the shell script version of linkgit:git-stash[1] will be removed in some
-future release.
-+
-If you find some reason to set this option to `false`, other than
-one-off testing, you should report the behavior difference as a bug in
-Git (see https://git-scm.com/community for details).
+	Unused configuration variable.  Used in Git versions 2.22 to
+	2.26 as an escape hatch to enable the legacy shellscript
+	implementation of stash.  Now the built-in rewrite of it in C
+	is always used. Setting this will emit a warning, to alert any
+	remaining users that setting this now does nothing.
 
 stash.showPatch::
 	If this is set to true, the `git stash show` command without an
diff --git a/Makefile b/Makefile
index a5961113d8..ef1ff2228f 100644
--- a/Makefile
+++ b/Makefile
@@ -609,7 +609,6 @@ SCRIPT_SH += git-merge-one-file.sh
 SCRIPT_SH += git-merge-resolve.sh
 SCRIPT_SH += git-mergetool.sh
 SCRIPT_SH += git-quiltimport.sh
-SCRIPT_SH += git-legacy-stash.sh
 SCRIPT_SH += git-request-pull.sh
 SCRIPT_SH += git-submodule.sh
 SCRIPT_SH += git-web--browse.sh
diff --git a/builtin/stash.c b/builtin/stash.c
index 78af6ce564..6d586ef06d 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -702,6 +702,7 @@ static int list_stash(int argc, const char **argv, const char *prefix)
 
 static int show_stat = 1;
 static int show_patch;
+static int use_legacy_stash;
 
 static int git_stash_config(const char *var, const char *value, void *cb)
 {
@@ -713,7 +714,11 @@ static int git_stash_config(const char *var, const char *value, void *cb)
 		show_patch = git_config_bool(var, value);
 		return 0;
 	}
-	return git_default_config(var, value, cb);
+	if (!strcmp(var, "stash.usebuiltin")) {
+		use_legacy_stash = !git_config_bool(var, value);
+		return 0;
+	}
+	return git_diff_basic_config(var, value, cb);
 }
 
 static int show_stash(int argc, const char **argv, const char *prefix)
@@ -750,7 +755,6 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	 * any options.
 	 */
 	if (revision_args.argc == 1) {
-		git_config(git_stash_config, NULL);
 		if (show_stat)
 			rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT;
 
@@ -1559,29 +1563,6 @@ static int save_stash(int argc, const char **argv, const char *prefix)
 	return ret;
 }
 
-static int use_builtin_stash(void)
-{
-	struct child_process cp = CHILD_PROCESS_INIT;
-	struct strbuf out = STRBUF_INIT;
-	int ret, env = git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1);
-
-	if (env != -1)
-		return env;
-
-	argv_array_pushl(&cp.args,
-			 "config", "--bool", "stash.usebuiltin", NULL);
-	cp.git_cmd = 1;
-	if (capture_command(&cp, &out, 6)) {
-		strbuf_release(&out);
-		return 1;
-	}
-
-	strbuf_trim(&out);
-	ret = !strcmp("true", out.buf);
-	strbuf_release(&out);
-	return ret;
-}
-
 int cmd_stash(int argc, const char **argv, const char *prefix)
 {
 	pid_t pid = getpid();
@@ -1592,21 +1573,12 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	if (!use_builtin_stash()) {
-		const char *path = mkpath("%s/git-legacy-stash",
-					  git_exec_path());
+	git_config(git_stash_config, NULL);
 
-		if (sane_execvp(path, (char **)argv) < 0)
-			die_errno(_("could not exec %s"), path);
-		else
-			BUG("sane_execvp() returned???");
-	}
-
-	prefix = setup_git_directory();
-	trace_repo_setup(prefix);
-	setup_work_tree();
-
-	git_config(git_diff_basic_config, NULL);
+	if (use_legacy_stash ||
+	    !git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1))
+		warning(_("the stash.useBuiltin support has been removed!\n"
+			  "See its entry in 'git help config' for details."));
 
 	argc = parse_options(argc, argv, prefix, options, git_stash_usage,
 			     PARSE_OPT_KEEP_UNKNOWN | PARSE_OPT_KEEP_DASHDASH);
diff --git a/git-legacy-stash.sh b/git-legacy-stash.sh
deleted file mode 100755
index 4d4ebb4f2b..0000000000
--- a/git-legacy-stash.sh
+++ /dev/null
@@ -1,798 +0,0 @@
-#!/bin/sh
-# Copyright (c) 2007, Nanako Shiraishi
-
-dashless=$(basename "$0" | sed -e 's/-/ /')
-USAGE="list [<options>]
-   or: $dashless show [<stash>]
-   or: $dashless drop [-q|--quiet] [<stash>]
-   or: $dashless ( pop | apply ) [--index] [-q|--quiet] [<stash>]
-   or: $dashless branch <branchname> [<stash>]
-   or: $dashless save [--patch] [-k|--[no-]keep-index] [-q|--quiet]
-		      [-u|--include-untracked] [-a|--all] [<message>]
-   or: $dashless [push [--patch] [-k|--[no-]keep-index] [-q|--quiet]
-		       [-u|--include-untracked] [-a|--all] [-m <message>]
-		       [-- <pathspec>...]]
-   or: $dashless clear"
-
-SUBDIRECTORY_OK=Yes
-OPTIONS_SPEC=
-START_DIR=$(pwd)
-. git-sh-setup
-require_work_tree
-prefix=$(git rev-parse --show-prefix) || exit 1
-cd_to_toplevel
-
-TMP="$GIT_DIR/.git-stash.$$"
-TMPindex=${GIT_INDEX_FILE-"$(git rev-parse --git-path index)"}.stash.$$
-trap 'rm -f "$TMP-"* "$TMPindex"' 0
-
-ref_stash=refs/stash
-
-if git config --get-colorbool color.interactive; then
-       help_color="$(git config --get-color color.interactive.help 'red bold')"
-       reset_color="$(git config --get-color '' reset)"
-else
-       help_color=
-       reset_color=
-fi
-
-no_changes () {
-	git diff-index --quiet --cached HEAD --ignore-submodules -- "$@" &&
-	git diff-files --quiet --ignore-submodules -- "$@" &&
-	(test -z "$untracked" || test -z "$(untracked_files "$@")")
-}
-
-untracked_files () {
-	if test "$1" = "-z"
-	then
-		shift
-		z=-z
-	else
-		z=
-	fi
-	excl_opt=--exclude-standard
-	test "$untracked" = "all" && excl_opt=
-	git ls-files -o $z $excl_opt -- "$@"
-}
-
-prepare_fallback_ident () {
-	if ! git -c user.useconfigonly=yes var GIT_COMMITTER_IDENT >/dev/null 2>&1
-	then
-		GIT_AUTHOR_NAME="git stash"
-		GIT_AUTHOR_EMAIL=git@stash
-		GIT_COMMITTER_NAME="git stash"
-		GIT_COMMITTER_EMAIL=git@stash
-		export GIT_AUTHOR_NAME
-		export GIT_AUTHOR_EMAIL
-		export GIT_COMMITTER_NAME
-		export GIT_COMMITTER_EMAIL
-	fi
-}
-
-clear_stash () {
-	if test $# != 0
-	then
-		die "$(gettext "git stash clear with parameters is unimplemented")"
-	fi
-	if current=$(git rev-parse --verify --quiet $ref_stash)
-	then
-		git update-ref -d $ref_stash $current
-	fi
-}
-
-maybe_quiet () {
-	case "$1" in
-	--keep-stdout)
-		shift
-		if test -n "$GIT_QUIET"
-		then
-			"$@" 2>/dev/null
-		else
-			"$@"
-		fi
-		;;
-	*)
-		if test -n "$GIT_QUIET"
-		then
-			"$@" >/dev/null 2>&1
-		else
-			"$@"
-		fi
-		;;
-	esac
-}
-
-create_stash () {
-
-	prepare_fallback_ident
-
-	stash_msg=
-	untracked=
-	while test $# != 0
-	do
-		case "$1" in
-		-m|--message)
-			shift
-			stash_msg=${1?"BUG: create_stash () -m requires an argument"}
-			;;
-		-m*)
-			stash_msg=${1#-m}
-			;;
-		--message=*)
-			stash_msg=${1#--message=}
-			;;
-		-u|--include-untracked)
-			shift
-			untracked=${1?"BUG: create_stash () -u requires an argument"}
-			;;
-		--)
-			shift
-			break
-			;;
-		esac
-		shift
-	done
-
-	git update-index -q --refresh
-	if maybe_quiet no_changes "$@"
-	then
-		exit 0
-	fi
-
-	# state of the base commit
-	if b_commit=$(maybe_quiet --keep-stdout git rev-parse --verify HEAD)
-	then
-		head=$(git rev-list --oneline -n 1 HEAD --)
-	elif test -n "$GIT_QUIET"
-	then
-		exit 1
-	else
-		die "$(gettext "You do not have the initial commit yet")"
-	fi
-
-	if branch=$(git symbolic-ref -q HEAD)
-	then
-		branch=${branch#refs/heads/}
-	else
-		branch='(no branch)'
-	fi
-	msg=$(printf '%s: %s' "$branch" "$head")
-
-	# state of the index
-	i_tree=$(git write-tree) &&
-	i_commit=$(printf 'index on %s\n' "$msg" |
-		git commit-tree $i_tree -p $b_commit) ||
-		die "$(gettext "Cannot save the current index state")"
-
-	if test -n "$untracked"
-	then
-		# Untracked files are stored by themselves in a parentless commit, for
-		# ease of unpacking later.
-		u_commit=$(
-			untracked_files -z "$@" | (
-				GIT_INDEX_FILE="$TMPindex" &&
-				export GIT_INDEX_FILE &&
-				rm -f "$TMPindex" &&
-				git update-index -z --add --remove --stdin &&
-				u_tree=$(git write-tree) &&
-				printf 'untracked files on %s\n' "$msg" | git commit-tree $u_tree  &&
-				rm -f "$TMPindex"
-		) ) || die "$(gettext "Cannot save the untracked files")"
-
-		untracked_commit_option="-p $u_commit";
-	else
-		untracked_commit_option=
-	fi
-
-	if test -z "$patch_mode"
-	then
-
-		# state of the working tree
-		w_tree=$( (
-			git read-tree --index-output="$TMPindex" -m $i_tree &&
-			GIT_INDEX_FILE="$TMPindex" &&
-			export GIT_INDEX_FILE &&
-			git diff-index --name-only -z HEAD -- "$@" >"$TMP-stagenames" &&
-			git update-index --ignore-skip-worktree-entries \
-				-z --add --remove --stdin <"$TMP-stagenames" &&
-			git write-tree &&
-			rm -f "$TMPindex"
-		) ) ||
-			die "$(gettext "Cannot save the current worktree state")"
-
-	else
-
-		rm -f "$TMP-index" &&
-		GIT_INDEX_FILE="$TMP-index" git read-tree HEAD &&
-
-		# find out what the user wants
-		GIT_INDEX_FILE="$TMP-index" \
-			git add --legacy-stash-p -- "$@" &&
-
-		# state of the working tree
-		w_tree=$(GIT_INDEX_FILE="$TMP-index" git write-tree) ||
-		die "$(gettext "Cannot save the current worktree state")"
-
-		git diff-tree -p HEAD $w_tree -- >"$TMP-patch" &&
-		test -s "$TMP-patch" ||
-		die "$(gettext "No changes selected")"
-
-		rm -f "$TMP-index" ||
-		die "$(gettext "Cannot remove temporary index (can't happen)")"
-
-	fi
-
-	# create the stash
-	if test -z "$stash_msg"
-	then
-		stash_msg=$(printf 'WIP on %s' "$msg")
-	else
-		stash_msg=$(printf 'On %s: %s' "$branch" "$stash_msg")
-	fi
-	w_commit=$(printf '%s\n' "$stash_msg" |
-	git commit-tree $w_tree -p $b_commit -p $i_commit $untracked_commit_option) ||
-	die "$(gettext "Cannot record working tree state")"
-}
-
-store_stash () {
-	while test $# != 0
-	do
-		case "$1" in
-		-m|--message)
-			shift
-			stash_msg="$1"
-			;;
-		-m*)
-			stash_msg=${1#-m}
-			;;
-		--message=*)
-			stash_msg=${1#--message=}
-			;;
-		-q|--quiet)
-			quiet=t
-			;;
-		*)
-			break
-			;;
-		esac
-		shift
-	done
-	test $# = 1 ||
-	die "$(eval_gettext "\"$dashless store\" requires one <commit> argument")"
-
-	w_commit="$1"
-	if test -z "$stash_msg"
-	then
-		stash_msg="Created via \"git stash store\"."
-	fi
-
-	git update-ref --create-reflog -m "$stash_msg" $ref_stash $w_commit
-	ret=$?
-	test $ret != 0 && test -z "$quiet" &&
-	die "$(eval_gettext "Cannot update \$ref_stash with \$w_commit")"
-	return $ret
-}
-
-push_stash () {
-	keep_index=
-	patch_mode=
-	untracked=
-	stash_msg=
-	while test $# != 0
-	do
-		case "$1" in
-		-k|--keep-index)
-			keep_index=t
-			;;
-		--no-keep-index)
-			keep_index=n
-			;;
-		-p|--patch)
-			patch_mode=t
-			# only default to keep if we don't already have an override
-			test -z "$keep_index" && keep_index=t
-			;;
-		-q|--quiet)
-			GIT_QUIET=t
-			;;
-		-u|--include-untracked)
-			untracked=untracked
-			;;
-		-a|--all)
-			untracked=all
-			;;
-		-m|--message)
-			shift
-			test -z ${1+x} && usage
-			stash_msg=$1
-			;;
-		-m*)
-			stash_msg=${1#-m}
-			;;
-		--message=*)
-			stash_msg=${1#--message=}
-			;;
-		--help)
-			show_help
-			;;
-		--)
-			shift
-			break
-			;;
-		-*)
-			option="$1"
-			eval_gettextln "error: unknown option for 'stash push': \$option"
-			usage
-			;;
-		*)
-			break
-			;;
-		esac
-		shift
-	done
-
-	eval "set $(git rev-parse --sq --prefix "$prefix" -- "$@")"
-
-	if test -n "$patch_mode" && test -n "$untracked"
-	then
-		die "$(gettext "Can't use --patch and --include-untracked or --all at the same time")"
-	fi
-
-	test -n "$untracked" || git ls-files --error-unmatch -- "$@" >/dev/null || exit 1
-
-	git update-index -q --refresh
-	if maybe_quiet no_changes "$@"
-	then
-		say "$(gettext "No local changes to save")"
-		exit 0
-	fi
-
-	git reflog exists $ref_stash ||
-		clear_stash || die "$(gettext "Cannot initialize stash")"
-
-	create_stash -m "$stash_msg" -u "$untracked" -- "$@"
-	store_stash -m "$stash_msg" -q $w_commit ||
-	die "$(gettext "Cannot save the current status")"
-	say "$(eval_gettext "Saved working directory and index state \$stash_msg")"
-
-	if test -z "$patch_mode"
-	then
-		test "$untracked" = "all" && CLEAN_X_OPTION=-x || CLEAN_X_OPTION=
-		if test -n "$untracked" && test $# = 0
-		then
-			git clean --force --quiet -d $CLEAN_X_OPTION
-		fi
-
-		if test $# != 0
-		then
-			test -z "$untracked" && UPDATE_OPTION="-u" || UPDATE_OPTION=
-			test "$untracked" = "all" && FORCE_OPTION="--force" || FORCE_OPTION=
-			git add $UPDATE_OPTION $FORCE_OPTION -- "$@"
-			git diff-index -p --cached --binary HEAD -- "$@" |
-			git apply --index -R
-		else
-			git reset --hard -q --no-recurse-submodules
-		fi
-
-		if test "$keep_index" = "t" && test -n "$i_tree"
-		then
-			git read-tree --reset $i_tree
-			git ls-files -z --modified -- "$@" |
-			git checkout-index -z --force --stdin
-		fi
-	else
-		git apply -R < "$TMP-patch" ||
-		die "$(gettext "Cannot remove worktree changes")"
-
-		if test "$keep_index" != "t"
-		then
-			git reset -q -- "$@"
-		fi
-	fi
-}
-
-save_stash () {
-	push_options=
-	while test $# != 0
-	do
-		case "$1" in
-		-q|--quiet)
-			GIT_QUIET=t
-			;;
-		--)
-			shift
-			break
-			;;
-		-*)
-			# pass all options through to push_stash
-			push_options="$push_options $1"
-			;;
-		*)
-			break
-			;;
-		esac
-		shift
-	done
-
-	stash_msg="$*"
-
-	if test -z "$stash_msg"
-	then
-		push_stash $push_options
-	else
-		push_stash $push_options -m "$stash_msg"
-	fi
-}
-
-have_stash () {
-	git rev-parse --verify --quiet $ref_stash >/dev/null
-}
-
-list_stash () {
-	have_stash || return 0
-	git log --format="%gd: %gs" -g --first-parent -m "$@" $ref_stash --
-}
-
-show_stash () {
-	ALLOW_UNKNOWN_FLAGS=t
-	assert_stash_like "$@"
-
-	if test -z "$FLAGS"
-	then
-		if test "$(git config --bool stash.showStat || echo true)" = "true"
-		then
-			FLAGS=--stat
-		fi
-
-		if test "$(git config --bool stash.showPatch || echo false)" = "true"
-		then
-			FLAGS=${FLAGS}${FLAGS:+ }-p
-		fi
-
-		if test -z "$FLAGS"
-		then
-			return 0
-		fi
-	fi
-
-	git diff ${FLAGS} $b_commit $w_commit
-}
-
-show_help () {
-	exec git help stash
-	exit 1
-}
-
-#
-# Parses the remaining options looking for flags and
-# at most one revision defaulting to ${ref_stash}@{0}
-# if none found.
-#
-# Derives related tree and commit objects from the
-# revision, if one is found.
-#
-# stash records the work tree, and is a merge between the
-# base commit (first parent) and the index tree (second parent).
-#
-#   REV is set to the symbolic version of the specified stash-like commit
-#   IS_STASH_LIKE is non-blank if ${REV} looks like a stash
-#   IS_STASH_REF is non-blank if the ${REV} looks like a stash ref
-#   s is set to the SHA1 of the stash commit
-#   w_commit is set to the commit containing the working tree
-#   b_commit is set to the base commit
-#   i_commit is set to the commit containing the index tree
-#   u_commit is set to the commit containing the untracked files tree
-#   w_tree is set to the working tree
-#   b_tree is set to the base tree
-#   i_tree is set to the index tree
-#   u_tree is set to the untracked files tree
-#
-#   GIT_QUIET is set to t if -q is specified
-#   INDEX_OPTION is set to --index if --index is specified.
-#   FLAGS is set to the remaining flags (if allowed)
-#
-# dies if:
-#   * too many revisions specified
-#   * no revision is specified and there is no stash stack
-#   * a revision is specified which cannot be resolve to a SHA1
-#   * a non-existent stash reference is specified
-#   * unknown flags were set and ALLOW_UNKNOWN_FLAGS is not "t"
-#
-
-parse_flags_and_rev()
-{
-	test "$PARSE_CACHE" = "$*" && return 0 # optimisation
-	PARSE_CACHE="$*"
-
-	IS_STASH_LIKE=
-	IS_STASH_REF=
-	INDEX_OPTION=
-	s=
-	w_commit=
-	b_commit=
-	i_commit=
-	u_commit=
-	w_tree=
-	b_tree=
-	i_tree=
-	u_tree=
-
-	FLAGS=
-	REV=
-	for opt
-	do
-		case "$opt" in
-			-q|--quiet)
-				GIT_QUIET=-t
-			;;
-			--index)
-				INDEX_OPTION=--index
-			;;
-			--help)
-				show_help
-			;;
-			-*)
-				test "$ALLOW_UNKNOWN_FLAGS" = t ||
-					die "$(eval_gettext "unknown option: \$opt")"
-				FLAGS="${FLAGS}${FLAGS:+ }$opt"
-			;;
-			*)
-				REV="${REV}${REV:+ }'$opt'"
-			;;
-		esac
-	done
-
-	eval set -- $REV
-
-	case $# in
-		0)
-			have_stash || die "$(gettext "No stash entries found.")"
-			set -- ${ref_stash}@{0}
-		;;
-		1)
-			:
-		;;
-		*)
-			die "$(eval_gettext "Too many revisions specified: \$REV")"
-		;;
-	esac
-
-	case "$1" in
-		*[!0-9]*)
-			:
-		;;
-		*)
-			set -- "${ref_stash}@{$1}"
-		;;
-	esac
-
-	REV=$(git rev-parse --symbolic --verify --quiet "$1") || {
-		reference="$1"
-		die "$(eval_gettext "\$reference is not a valid reference")"
-	}
-
-	i_commit=$(git rev-parse --verify --quiet "$REV^2") &&
-	set -- $(git rev-parse "$REV" "$REV^1" "$REV:" "$REV^1:" "$REV^2:" 2>/dev/null) &&
-	s=$1 &&
-	w_commit=$1 &&
-	b_commit=$2 &&
-	w_tree=$3 &&
-	b_tree=$4 &&
-	i_tree=$5 &&
-	IS_STASH_LIKE=t &&
-	test "$ref_stash" = "$(git rev-parse --symbolic-full-name "${REV%@*}")" &&
-	IS_STASH_REF=t
-
-	u_commit=$(git rev-parse --verify --quiet "$REV^3") &&
-	u_tree=$(git rev-parse "$REV^3:" 2>/dev/null)
-}
-
-is_stash_like()
-{
-	parse_flags_and_rev "$@"
-	test -n "$IS_STASH_LIKE"
-}
-
-assert_stash_like() {
-	is_stash_like "$@" || {
-		args="$*"
-		die "$(eval_gettext "'\$args' is not a stash-like commit")"
-	}
-}
-
-is_stash_ref() {
-	is_stash_like "$@" && test -n "$IS_STASH_REF"
-}
-
-assert_stash_ref() {
-	is_stash_ref "$@" || {
-		args="$*"
-		die "$(eval_gettext "'\$args' is not a stash reference")"
-	}
-}
-
-apply_stash () {
-
-	assert_stash_like "$@"
-
-	git update-index -q --refresh || die "$(gettext "unable to refresh index")"
-
-	# current index state
-	c_tree=$(git write-tree) ||
-		die "$(gettext "Cannot apply a stash in the middle of a merge")"
-
-	unstashed_index_tree=
-	if test -n "$INDEX_OPTION" && test "$b_tree" != "$i_tree" &&
-			test "$c_tree" != "$i_tree"
-	then
-		git diff-tree --binary $s^2^..$s^2 | git apply --cached
-		test $? -ne 0 &&
-			die "$(gettext "Conflicts in index. Try without --index.")"
-		unstashed_index_tree=$(git write-tree) ||
-			die "$(gettext "Could not save index tree")"
-		git reset
-	fi
-
-	if test -n "$u_tree"
-	then
-		GIT_INDEX_FILE="$TMPindex" git read-tree "$u_tree" &&
-		GIT_INDEX_FILE="$TMPindex" git checkout-index --all &&
-		rm -f "$TMPindex" ||
-		die "$(gettext "Could not restore untracked files from stash entry")"
-	fi
-
-	eval "
-		GITHEAD_$w_tree='Stashed changes' &&
-		GITHEAD_$c_tree='Updated upstream' &&
-		GITHEAD_$b_tree='Version stash was based on' &&
-		export GITHEAD_$w_tree GITHEAD_$c_tree GITHEAD_$b_tree
-	"
-
-	if test -n "$GIT_QUIET"
-	then
-		GIT_MERGE_VERBOSITY=0 && export GIT_MERGE_VERBOSITY
-	fi
-	if git merge-recursive $b_tree -- $c_tree $w_tree
-	then
-		# No conflict
-		if test -n "$unstashed_index_tree"
-		then
-			git read-tree "$unstashed_index_tree"
-		else
-			a="$TMP-added" &&
-			git diff-index --cached --name-only --diff-filter=A $c_tree >"$a" &&
-			git read-tree --reset $c_tree &&
-			git update-index --add --stdin <"$a" ||
-				die "$(gettext "Cannot unstage modified files")"
-			rm -f "$a"
-		fi
-		squelch=
-		if test -n "$GIT_QUIET"
-		then
-			squelch='>/dev/null 2>&1'
-		fi
-		(cd "$START_DIR" && eval "git status $squelch") || :
-	else
-		# Merge conflict; keep the exit status from merge-recursive
-		status=$?
-		git rerere
-		if test -n "$INDEX_OPTION"
-		then
-			gettextln "Index was not unstashed." >&2
-		fi
-		exit $status
-	fi
-}
-
-pop_stash() {
-	assert_stash_ref "$@"
-
-	if apply_stash "$@"
-	then
-		drop_stash "$@"
-	else
-		status=$?
-		say "$(gettext "The stash entry is kept in case you need it again.")"
-		exit $status
-	fi
-}
-
-drop_stash () {
-	assert_stash_ref "$@"
-
-	git reflog delete --updateref --rewrite "${REV}" &&
-		say "$(eval_gettext "Dropped \${REV} (\$s)")" ||
-		die "$(eval_gettext "\${REV}: Could not drop stash entry")"
-
-	# clear_stash if we just dropped the last stash entry
-	git rev-parse --verify --quiet "$ref_stash@{0}" >/dev/null ||
-	clear_stash
-}
-
-apply_to_branch () {
-	test -n "$1" || die "$(gettext "No branch name specified")"
-	branch=$1
-	shift 1
-
-	set -- --index "$@"
-	assert_stash_like "$@"
-
-	git checkout -b $branch $REV^ &&
-	apply_stash "$@" && {
-		test -z "$IS_STASH_REF" || drop_stash "$@"
-	}
-}
-
-test "$1" = "-p" && set "push" "$@"
-
-PARSE_CACHE='--not-parsed'
-# The default command is "push" if nothing but options are given
-seen_non_option=
-for opt
-do
-	case "$opt" in
-	--) break ;;
-	-*) ;;
-	*) seen_non_option=t; break ;;
-	esac
-done
-
-test -n "$seen_non_option" || set "push" "$@"
-
-# Main command set
-case "$1" in
-list)
-	shift
-	list_stash "$@"
-	;;
-show)
-	shift
-	show_stash "$@"
-	;;
-save)
-	shift
-	save_stash "$@"
-	;;
-push)
-	shift
-	push_stash "$@"
-	;;
-apply)
-	shift
-	apply_stash "$@"
-	;;
-clear)
-	shift
-	clear_stash "$@"
-	;;
-create)
-	shift
-	create_stash -m "$*" && echo "$w_commit"
-	;;
-store)
-	shift
-	store_stash "$@"
-	;;
-drop)
-	shift
-	drop_stash "$@"
-	;;
-pop)
-	shift
-	pop_stash "$@"
-	;;
-branch)
-	shift
-	apply_to_branch "$@"
-	;;
-*)
-	case $# in
-	0)
-		push_stash &&
-		say "$(gettext "(To restore them type \"git stash apply\")")"
-		;;
-	*)
-		usage
-	esac
-	;;
-esac
diff --git a/git.c b/git.c
index 7be7ad34bd..b07198fe03 100644
--- a/git.c
+++ b/git.c
@@ -574,12 +574,7 @@ static struct cmd_struct commands[] = {
 	{ "show-ref", cmd_show_ref, RUN_SETUP },
 	{ "sparse-checkout", cmd_sparse_checkout, RUN_SETUP | NEED_WORK_TREE },
 	{ "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
-	/*
-	 * NEEDSWORK: Until the builtin stash is thoroughly robust and no
-	 * longer needs redirection to the stash shell script this is kept as
-	 * is, then should be changed to RUN_SETUP | NEED_WORK_TREE
-	 */
-	{ "stash", cmd_stash },
+	{ "stash", cmd_stash, RUN_SETUP | NEED_WORK_TREE },
 	{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
 	{ "stripspace", cmd_stripspace },
 	{ "submodule--helper", cmd_submodule__helper, RUN_SETUP | SUPPORT_SUPER_PREFIX | NO_PARSEOPT },
diff --git a/t/README b/t/README
index 9afd61e3ca..369e3a9ded 100644
--- a/t/README
+++ b/t/README
@@ -393,10 +393,6 @@ the --no-sparse command-line argument.
 GIT_TEST_PRELOAD_INDEX=<boolean> exercises the preload-index code path
 by overriding the minimum number of cache entries required per thread.
 
-GIT_TEST_STASH_USE_BUILTIN=<boolean>, when false, disables the
-built-in version of git-stash. See 'stash.useBuiltin' in
-git-config(1).
-
 GIT_TEST_ADD_I_USE_BUILTIN=<boolean>, when true, enables the
 built-in version of git add -i. See 'add.interactive.useBuiltin' in
 git-config(1).
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 3ad23e2502..9f7ca98967 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -1290,4 +1290,18 @@ test_expect_success 'stash handles skip-worktree entries nicely' '
 	git rev-parse --verify refs/stash:A.t
 '
 
+test_expect_success 'stash -c stash.useBuiltin=false warning ' '
+	expected="stash.useBuiltin support has been removed" &&
+
+	git -c stash.useBuiltin=false stash 2>err &&
+	test_i18ngrep "$expected" err &&
+	env GIT_TEST_STASH_USE_BUILTIN=false git stash 2>err &&
+	test_i18ngrep "$expected" err &&
+
+	git -c stash.useBuiltin=true stash 2>err &&
+	test_must_be_empty err &&
+	env GIT_TEST_STASH_USE_BUILTIN=true git stash 2>err &&
+	test_must_be_empty err
+'
+
 test_done