diff --git a/t/t5703-upload-pack-ref-in-want.sh b/t/t5703-upload-pack-ref-in-want.sh
index 3dad21ff45..220098523a 100755
--- a/t/t5703-upload-pack-ref-in-want.sh
+++ b/t/t5703-upload-pack-ref-in-want.sh
@@ -299,6 +299,141 @@ test_expect_success 'fetching with wildcard that matches multiple refs' '
 	grep "want-ref refs/heads/o/bar" log
 '
 
+REPO="$(pwd)/repo-ns"
+
+test_expect_success 'setup namespaced repo' '
+	(
+		git init -b main "$REPO" &&
+		cd "$REPO" &&
+		test_commit a &&
+		test_commit b &&
+		git checkout a &&
+		test_commit c &&
+		git checkout a &&
+		test_commit d &&
+		git update-ref refs/heads/ns-no b &&
+		git update-ref refs/namespaces/ns/refs/heads/ns-yes c &&
+		git update-ref refs/namespaces/ns/refs/heads/hidden d
+	) &&
+	git -C "$REPO" config uploadpack.allowRefInWant true
+'
+
+test_expect_success 'with namespace: want-ref is considered relative to namespace' '
+	wanted_ref=refs/heads/ns-yes &&
+
+	oid=$(git -C "$REPO" rev-parse "refs/namespaces/ns/$wanted_ref") &&
+	cat >expected_refs <<-EOF &&
+	$oid $wanted_ref
+	EOF
+	cat >expected_commits <<-EOF &&
+	$oid
+	$(git -C "$REPO" rev-parse a)
+	EOF
+
+	write_fetch_command >pkt <<-EOF &&
+	want-ref $wanted_ref
+	EOF
+	test-tool pkt-line pack <pkt >in &&
+
+	GIT_NAMESPACE=ns test-tool -C "$REPO" serve-v2 --stateless-rpc >out <in &&
+	check_output
+'
+
+test_expect_success 'with namespace: want-ref outside namespace is unknown' '
+	wanted_ref=refs/heads/ns-no &&
+
+	write_fetch_command >pkt <<-EOF &&
+	want-ref $wanted_ref
+	EOF
+	test-tool pkt-line pack <pkt >in &&
+
+	test_must_fail env GIT_NAMESPACE=ns \
+		test-tool -C "$REPO" serve-v2 --stateless-rpc >out <in &&
+	grep "unknown ref" out
+'
+
+# Cross-check refs/heads/ns-no indeed exists
+test_expect_success 'without namespace: want-ref outside namespace succeeds' '
+	wanted_ref=refs/heads/ns-no &&
+
+	oid=$(git -C "$REPO" rev-parse $wanted_ref) &&
+	cat >expected_refs <<-EOF &&
+	$oid $wanted_ref
+	EOF
+	cat >expected_commits <<-EOF &&
+	$oid
+	$(git -C "$REPO" rev-parse a)
+	EOF
+
+	write_fetch_command >pkt <<-EOF &&
+	want-ref $wanted_ref
+	EOF
+	test-tool pkt-line pack <pkt >in &&
+
+	test-tool -C "$REPO" serve-v2 --stateless-rpc >out <in &&
+	check_output
+'
+
+test_expect_success 'with namespace: hideRefs is matched, relative to namespace' '
+	wanted_ref=refs/heads/hidden &&
+	git -C "$REPO" config transfer.hideRefs $wanted_ref &&
+
+	write_fetch_command >pkt <<-EOF &&
+	want-ref $wanted_ref
+	EOF
+	test-tool pkt-line pack <pkt >in &&
+
+	test_must_fail env GIT_NAMESPACE=ns \
+		test-tool -C "$REPO" serve-v2 --stateless-rpc >out <in &&
+	grep "unknown ref" out
+'
+
+# Cross-check refs/heads/hidden indeed exists
+test_expect_success 'with namespace: want-ref succeeds if hideRefs is removed' '
+	wanted_ref=refs/heads/hidden &&
+	git -C "$REPO" config --unset transfer.hideRefs $wanted_ref &&
+
+	oid=$(git -C "$REPO" rev-parse "refs/namespaces/ns/$wanted_ref") &&
+	cat >expected_refs <<-EOF &&
+	$oid $wanted_ref
+	EOF
+	cat >expected_commits <<-EOF &&
+	$oid
+	$(git -C "$REPO" rev-parse a)
+	EOF
+
+	write_fetch_command >pkt <<-EOF &&
+	want-ref $wanted_ref
+	EOF
+	test-tool pkt-line pack <pkt >in &&
+
+	GIT_NAMESPACE=ns test-tool -C "$REPO" serve-v2 --stateless-rpc >out <in &&
+	check_output
+'
+
+test_expect_success 'without namespace: relative hideRefs does not match' '
+	wanted_ref=refs/namespaces/ns/refs/heads/hidden &&
+	git -C "$REPO" config transfer.hideRefs refs/heads/hidden &&
+
+	oid=$(git -C "$REPO" rev-parse $wanted_ref) &&
+	cat >expected_refs <<-EOF &&
+	$oid $wanted_ref
+	EOF
+	cat >expected_commits <<-EOF &&
+	$oid
+	$(git -C "$REPO" rev-parse a)
+	EOF
+
+	write_fetch_command >pkt <<-EOF &&
+	want-ref $wanted_ref
+	EOF
+	test-tool pkt-line pack <pkt >in &&
+
+	test-tool -C "$REPO" serve-v2 --stateless-rpc >out <in &&
+	check_output
+'
+
+
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
 
diff --git a/upload-pack.c b/upload-pack.c
index 297b76fcb4..6ce07231d3 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1417,21 +1417,25 @@ static int parse_want_ref(struct packet_writer *writer, const char *line,
 			  struct string_list *wanted_refs,
 			  struct object_array *want_obj)
 {
-	const char *arg;
-	if (skip_prefix(line, "want-ref ", &arg)) {
+	const char *refname_nons;
+	if (skip_prefix(line, "want-ref ", &refname_nons)) {
 		struct object_id oid;
 		struct string_list_item *item;
 		struct object *o;
+		struct strbuf refname = STRBUF_INIT;
 
-		if (read_ref(arg, &oid)) {
-			packet_writer_error(writer, "unknown ref %s", arg);
-			die("unknown ref %s", arg);
+		strbuf_addf(&refname, "%s%s", get_git_namespace(), refname_nons);
+		if (ref_is_hidden(refname_nons, refname.buf) ||
+		    read_ref(refname.buf, &oid)) {
+			packet_writer_error(writer, "unknown ref %s", refname_nons);
+			die("unknown ref %s", refname_nons);
 		}
+		strbuf_release(&refname);
 
-		item = string_list_append(wanted_refs, arg);
+		item = string_list_append(wanted_refs, refname_nons);
 		item->util = oiddup(&oid);
 
-		o = parse_object_or_die(&oid, arg);
+		o = parse_object_or_die(&oid, refname_nons);
 		if (!(o->flags & WANTED)) {
 			o->flags |= WANTED;
 			add_object_array(o, NULL, want_obj);