diff --git a/client/lib/lib.go b/client/lib/lib.go
index cc4758c..815d42d 100644
--- a/client/lib/lib.go
+++ b/client/lib/lib.go
@@ -2,6 +2,7 @@ package lib
 
 import (
 	"bytes"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -13,6 +14,7 @@ import (
 	"os/exec"
 	"os/user"
 	"path"
+	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
@@ -539,6 +541,14 @@ func Update() error {
 		}
 	}
 
+	// On MacOS, set the xattrs containing the signatures. These are generated by an action and pushed to a github release that we download and set
+	if runtime.GOOS == "darwin" {
+		err := setCodesigningXattrs(downloadData, "/tmp/hishtory-client")
+		if err != nil {
+			return fmt.Errorf("failed to set codesigning xattrs: %v", err)
+		}
+	}
+
 	// Install the new one
 	cmd := exec.Command("chmod", "+x", "/tmp/hishtory-client")
 	var stdout bytes.Buffer
@@ -708,3 +718,72 @@ func ApiPost(path, contentType string, data []byte) ([]byte, error) {
 	getLogger().Printf("ApiPost(%#v): %s\n", path, duration.String())
 	return respBody, nil
 }
+
+func parseXattr(xattrDump string) (map[string][]byte, error) {
+	m := make(map[string][]byte)
+	nextLineIsAttrName := true
+	attrName := ""
+	attrValue := make([]byte, 0)
+	for _, line := range strings.Split(xattrDump, "\n") {
+		if nextLineIsAttrName {
+			attrName = line[:len(line)-1]
+			nextLineIsAttrName = false
+		} else {
+			r := regexp.MustCompile("\\d{8}  (?P<hex>([A-Z0-9]{2} )+)\\s+\\|[^\\s]+\\|")
+			match := r.FindStringSubmatch(line)
+			if match != nil {
+				for i, name := range r.SubexpNames() {
+					if name == "hex" {
+						bytes, err := hex.DecodeString(strings.ReplaceAll(match[i], " ", ""))
+						if err != nil {
+							return nil, fmt.Errorf("failed to decode hex string %#v in xattr file: %v", match[i], err)
+						}
+						attrValue = append(attrValue, bytes...)
+					}
+				}
+			} else {
+				if strings.Contains(line, "|") {
+					return nil, fmt.Errorf("entered confusing state in xattr file on line %#v, file=%#v", line, xattrDump)
+				} else {
+					nextLineIsAttrName = true
+					m[attrName] = attrValue
+					attrValue = make([]byte, 0)
+				}
+			}
+		}
+	}
+	return m, nil
+}
+
+func setXattr(filename, xattrDump string) {
+	m, err := parseXattr(xattrDump)
+	if err != nil {
+		panic(fmt.Errorf("failed to parse xattr file: %v", err))
+	}
+	for k, v := range m {
+		err := syscall.Setxattr(filename, k, v, 0)
+		if err != nil {
+			panic(fmt.Errorf("failed to set xattr %#v on file %#v: %v", k, filename, err))
+		}
+	}
+}
+
+func setCodesigningXattrs(downloadInfo shared.UpdateInfo, filename string) error {
+	if runtime.GOOS != "darwin" {
+		return fmt.Errorf("setCodesigningXattrs is only supported on macOS")
+	}
+	url := ""
+	if runtime.GOARCH == "arm64" {
+		url = downloadInfo.DarwinArm64Xattr
+	} else if runtime.GOARCH == "amd64" {
+		url = downloadInfo.DarwinAmd64Xattr
+	} else {
+		return fmt.Errorf("setCodesigningXattrs only supports arm64 and amd64: %#v", runtime.GOARCH)
+	}
+	xattrDump, err := ApiGet(url)
+	if err != nil {
+		return fmt.Errorf("failed to get xattr dump: %v", err)
+	}
+	setXattr(filename, string(xattrDump))
+	return nil
+}
diff --git a/client/lib/lib_test.go b/client/lib/lib_test.go
index ddfba98..65dff25 100644
--- a/client/lib/lib_test.go
+++ b/client/lib/lib_test.go
@@ -190,3 +190,57 @@ func TestParseCrossPlatformInt(t *testing.T) {
 		t.Fatalf("failed to parse cross platform int %d", res)
 	}
 }
+
+func TestParseXattr(t *testing.T) {
+	dump := `com.apple.macl:
+00000000  04 00 34 5A 0D 8F 9B 10 48 FB 9D 12 E2 11 C7 21  |................|
+00000010  D3 17 04 00 7D 17 C7 D7 51 B6 4B C4 B0 E5 1A 58  |................|
+00000020  21 53 DD 4C 00 00 00 00 00 00 00 00 00 00 00 00  |!S.L............|
+00000030  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  |................|
+00000040  00 00 00 00 00 00 00 00                          |........�......|
+00000048
+com.apple.metadata:kMDItemDownloadedDate:
+00000000  62 70 6C 69 73 74 30 30 A1 01 33 41 C4 07 D4 F5  |bplist00..3A....|
+00000010  D0 E7 A3 08 0A 00 00 00 00 00 00 01 01 00 00 00  |................|
+00000020  00 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00  |................|
+00000030  00 00 00 00 13                                   |.....|
+00000035
+com.apple.metadata:kMDItemWhereFroms:
+00000000  62 70 6C 69 73 74 30 30 A2 01 02 5F 10 47 68 74  |bplist00..._.Ght|
+00000010  74 70 73 3A 2F 2F 64 6C 2E 67 6F 6F 67 6C 65 2E  |tps://dl.google.|
+00000020  63 6F 6D 2F 63 68 72 6F 6D 65 2F 6D 61 63 2F 75  |com/chrome/mac/u|
+00000030  6E 69 76 65 72 73 61 6C 2F 73 74 61 62 6C 65 2F  |niversal/stable/|
+00000040  47 47 52 4F 2F 67 6F 6F 67 6C 65 63 68 72 6F 6D  |GGRO/googlechrom|
+00000050  65 2E 64 6D 67 5F 10 17 68 74 74 70 73 3A 2F 2F  |e.dmg_..https://|
+00000060  77 77 77 2E 67 6F 6F 67 6C 65 2E 63 6F 6D 2F 08  |www.google.com/.|
+00000092
+com.apple.quarantine:
+00000000  30 31 38 33 3B 36 32 35 66 37 32 36 62 3B 53 61  |0183;625f726b;Sa|
+00000010  66 61 72 69 3B 46 37 33 37 42 42 43 33 2D 30 41  |fari;F737BBC3-0A|
+00000020  35 38 2D 34 31 44 34 2D 38 46 33 36 2D 30 33 42  |58-41D4-8F36-03B|
+00000030  42 33 31 36 36 39 35 39 39                       |B31669599|
+00000039`
+	xattr, err := parseXattr(dump)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(xattr) != 4 {
+		t.Fatalf("xattr has an incorrect length: %d", len(xattr))
+	}
+	val := xattr["com.apple.quarantine"]
+	if string(val) != "0183;625f726b;Safari;F737BBC3-0A58-41D4-8F36-03BB31669599" {
+		t.Fatalf("unexpected xattr value=%#v", string(val))
+	}
+	val = xattr["com.apple.metadata:kMDItemWhereFroms"]
+	if string(val) != "bplist00\xa2\x01\x02_\x10Ghttps://dl.google.com/chrome/mac/universal/stable/GGRO/googlechrome.dmg_\x10\x17https://www.google.com/\b" {
+		t.Fatalf("unexpected xattr value=%#v", string(val))
+	}
+	val = xattr["com.apple.metadata:kMDItemDownloadedDate"]
+	if string(val) != "bplist00\xa1\x013A\xc4\a\xd4\xf5\xd0\xe7\xa3\b\n\x00\x00\x00\x00\x00\x00\x01\x01\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x13" {
+		t.Fatalf("unexpected xattr value=%#v", string(val))
+	}
+	val = xattr["com.apple.macl"]
+	if string(val) != "\x04\x004Z\r\x8f\x9b\x10H\xfb\x9d\x12\xe2\x11\xc7!\xd3\x17\x04\x00}\x17\xc7\xd7Q\xb6Kİ\xe5\x1aX!S\xddL\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" {
+		t.Fatalf("unexpected xattr value=%#v", string(val))
+	}
+}
diff --git a/shared/data.go b/shared/data.go
index b7c885f..d026a3d 100644
--- a/shared/data.go
+++ b/shared/data.go
@@ -30,8 +30,10 @@ type UpdateInfo struct {
 	LinuxAmd64AttestationUrl  string `json:"linux_amd_64_attestation_url"`
 	DarwinAmd64Url            string `json:"darwin_amd_64_url"`
 	DarwinAmd64AttestationUrl string `json:"darwin_amd_64_attestation_url"`
+	DarwinAmd64Xattr          string `json:"darwin_amd_64_xattr_url"`
 	DarwinArm64Url            string `json:"darwin_arm_64_url"`
 	DarwinArm64AttestationUrl string `json:"darwin_arm_64_attestation_url"`
+	DarwinArm64Xattr          string `json:"darwin_arm_64_xattr_url"`
 	Version                   string `json:"version"`
 }