diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 8e981c19..50ba06a9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -29,7 +29,7 @@ jobs:
         with: { name: go2rtc_win64, path: go2rtc.exe }
 
       - name: Build go2rtc_win32
-        env: { GOOS: windows, GOARCH: 386 }
+        env: { GOOS: windows, GOARCH: 386, GOTOOLCHAIN: go1.20.14 }
         run: go build -ldflags "-s -w" -trimpath
       - name: Upload go2rtc_win32
         uses: actions/upload-artifact@v4
@@ -85,7 +85,7 @@ jobs:
         with: { name: go2rtc_linux_mipsel, path: go2rtc }
 
       - name: Build go2rtc_mac_amd64
-        env: { GOOS: darwin, GOARCH: amd64 }
+        env: { GOOS: darwin, GOARCH: amd64, GOTOOLCHAIN: go1.20.14 }
         run: go build -ldflags "-s -w" -trimpath
       - name: Upload go2rtc_mac_amd64
         uses: actions/upload-artifact@v4
diff --git a/README.md b/README.md
index c31ed748..70ad4712 100644
--- a/README.md
+++ b/README.md
@@ -115,8 +115,8 @@ Ultimate camera streaming application with support RTSP, WebRTC, HomeKit, FFmpeg
 
 Download binary for your OS from [latest release](https://github.com/AlexxIT/go2rtc/releases/):
 
-- `go2rtc_win64.zip` - Windows 64-bit
-- `go2rtc_win32.zip` - Windows 32-bit
+- `go2rtc_win64.zip` - Windows 10+ 64-bit
+- `go2rtc_win32.zip` - Windows 7+ 32-bit
 - `go2rtc_win_arm64.zip` - Windows ARM 64-bit
 - `go2rtc_linux_amd64` - Linux 64-bit
 - `go2rtc_linux_i386` - Linux 32-bit
@@ -124,8 +124,8 @@ Download binary for your OS from [latest release](https://github.com/AlexxIT/go2
 - `go2rtc_linux_arm` - Linux ARM 32-bit (ex. Raspberry 32-bit OS)
 - `go2rtc_linux_armv6` - Linux ARMv6 (for old Raspberry 1 and Zero)
 - `go2rtc_linux_mipsel` - Linux MIPS (ex. [Xiaomi Gateway 3](https://github.com/AlexxIT/XiaomiGateway3), [Wyze cameras](https://github.com/gtxaspec/wz_mini_hacks))
-- `go2rtc_mac_amd64.zip` - Mac Intel 64-bit
-- `go2rtc_mac_arm64.zip` - Mac ARM 64-bit
+- `go2rtc_mac_amd64.zip` - macOS 10.13+ Intel 64-bit
+- `go2rtc_mac_arm64.zip` - macOS ARM 64-bit
 
 Don't forget to fix the rights `chmod +x go2rtc_xxx_xxx` on Linux and Mac.
 
diff --git a/go.mod b/go.mod
index d3cb791f..b038b110 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/AlexxIT/go2rtc
 
-go 1.22
+go 1.20
 
 require (
 	github.com/asticode/go-astits v1.13.0
diff --git a/internal/exec/exec.go b/internal/exec/exec.go
index 035317d9..bce166e8 100644
--- a/internal/exec/exec.go
+++ b/internal/exec/exec.go
@@ -10,7 +10,6 @@ import (
 	"net/url"
 	"os"
 	"os/exec"
-	"slices"
 	"strings"
 	"sync"
 	"time"
@@ -230,7 +229,7 @@ func trimSpace(b []byte) []byte {
 func setRemoteInfo(info core.Info, source string, args []string) {
 	info.SetSource(source)
 
-	if i := slices.Index(args, "-i"); i > 0 && i < len(args)-1 {
+	if i := core.Index(args, "-i"); i > 0 && i < len(args)-1 {
 		rawURL := args[i+1]
 		if u, err := url.Parse(rawURL); err == nil && u.Host != "" {
 			info.SetRemoteAddr(u.Host)
diff --git a/internal/ffmpeg/ffmpeg.go b/internal/ffmpeg/ffmpeg.go
index 062e5aaf..12a9be83 100644
--- a/internal/ffmpeg/ffmpeg.go
+++ b/internal/ffmpeg/ffmpeg.go
@@ -2,7 +2,6 @@ package ffmpeg
 
 import (
 	"net/url"
-	"slices"
 	"strings"
 
 	"github.com/AlexxIT/go2rtc/internal/api"
@@ -44,7 +43,7 @@ func Init() {
 			return "", err
 		}
 		args := parseArgs(url[7:])
-		if slices.Contains(args.Codecs, "auto") {
+		if core.Contains(args.Codecs, "auto") {
 			return "", nil // force call streams.HandleFunc("ffmpeg")
 		}
 		return "exec:" + args.String(), nil
diff --git a/internal/webrtc/candidates.go b/internal/webrtc/candidates.go
index b92c4656..adbfb4a7 100644
--- a/internal/webrtc/candidates.go
+++ b/internal/webrtc/candidates.go
@@ -2,10 +2,10 @@ package webrtc
 
 import (
 	"net"
-	"slices"
 	"strings"
 
 	"github.com/AlexxIT/go2rtc/internal/api/ws"
+	"github.com/AlexxIT/go2rtc/pkg/core"
 	"github.com/AlexxIT/go2rtc/pkg/webrtc"
 	pion "github.com/pion/webrtc/v3"
 )
@@ -75,14 +75,14 @@ func FilterCandidate(candidate *pion.ICECandidate) bool {
 
 	// host candidate should be in the hosts list
 	if candidate.Typ == pion.ICECandidateTypeHost && filters.Candidates != nil {
-		if !slices.Contains(filters.Candidates, candidate.Address) {
+		if !core.Contains(filters.Candidates, candidate.Address) {
 			return false
 		}
 	}
 
 	if filters.Networks != nil {
 		networkType := NetworkType(candidate.Protocol.String(), candidate.Address)
-		if !slices.Contains(filters.Networks, networkType) {
+		if !core.Contains(filters.Networks, networkType) {
 			return false
 		}
 	}
diff --git a/pkg/core/slices.go b/pkg/core/slices.go
new file mode 100644
index 00000000..747d813f
--- /dev/null
+++ b/pkg/core/slices.go
@@ -0,0 +1,43 @@
+package core
+
+// This code copied from go1.21 for backward support in go1.20.
+// We need to support go1.20 for Windows 7
+
+// Index returns the index of the first occurrence of v in s,
+// or -1 if not present.
+func Index[S ~[]E, E comparable](s S, v E) int {
+	for i := range s {
+		if v == s[i] {
+			return i
+		}
+	}
+	return -1
+}
+
+// Contains reports whether v is present in s.
+func Contains[S ~[]E, E comparable](s S, v E) bool {
+	return Index(s, v) >= 0
+}
+
+type Ordered interface {
+	~int | ~int8 | ~int16 | ~int32 | ~int64 |
+		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
+		~float32 | ~float64 |
+		~string
+}
+
+// Max returns the maximal value in x. It panics if x is empty.
+// For floating-point E, Max propagates NaNs (any NaN value in x
+// forces the output to be NaN).
+func Max[S ~[]E, E Ordered](x S) E {
+	if len(x) < 1 {
+		panic("slices.Max: empty list")
+	}
+	m := x[0]
+	for i := 1; i < len(x); i++ {
+		if x[i] > m {
+			m = x[i]
+		}
+	}
+	return m
+}
diff --git a/pkg/homekit/consumer.go b/pkg/homekit/consumer.go
index 1c665233..ea83146f 100644
--- a/pkg/homekit/consumer.go
+++ b/pkg/homekit/consumer.go
@@ -3,7 +3,7 @@ package homekit
 import (
 	"fmt"
 	"io"
-	"math/rand/v2"
+	"math/rand"
 	"net"
 	"time"
 
diff --git a/pkg/homekit/helpers.go b/pkg/homekit/helpers.go
index 89c63dc3..a1719671 100644
--- a/pkg/homekit/helpers.go
+++ b/pkg/homekit/helpers.go
@@ -2,7 +2,6 @@ package homekit
 
 import (
 	"encoding/hex"
-	"slices"
 
 	"github.com/AlexxIT/go2rtc/pkg/aac"
 	"github.com/AlexxIT/go2rtc/pkg/core"
@@ -22,8 +21,8 @@ func videoToMedia(codecs []camera.VideoCodec) *core.Media {
 	for _, codec := range codecs {
 		for _, param := range codec.CodecParams {
 			// get best profile and level
-			profileID := slices.Max(param.ProfileID)
-			level := slices.Max(param.Level)
+			profileID := core.Max(param.ProfileID)
+			level := core.Max(param.Level)
 			profile := videoProfiles[profileID] + videoLevels[level]
 			mediaCodec := &core.Codec{
 				Name:      videoCodecs[codec.CodecType],
diff --git a/pkg/webrtc/api.go b/pkg/webrtc/api.go
index f63cabfd..0361e6b4 100644
--- a/pkg/webrtc/api.go
+++ b/pkg/webrtc/api.go
@@ -2,8 +2,8 @@ package webrtc
 
 import (
 	"net"
-	"slices"
 
+	"github.com/AlexxIT/go2rtc/pkg/core"
 	"github.com/pion/interceptor"
 	"github.com/pion/webrtc/v3"
 )
@@ -47,7 +47,7 @@ func NewServerAPI(network, address string, filters *Filters) (*webrtc.API, error
 	if filters != nil && filters.Interfaces != nil {
 		s.SetIncludeLoopbackCandidate(true)
 		s.SetInterfaceFilter(func(name string) bool {
-			return slices.Contains(filters.Interfaces, name)
+			return core.Contains(filters.Interfaces, name)
 		})
 	} else {
 		// disable listen on Hassio docker interfaces
@@ -59,7 +59,7 @@ func NewServerAPI(network, address string, filters *Filters) (*webrtc.API, error
 	if filters != nil && filters.IPs != nil {
 		s.SetIncludeLoopbackCandidate(true)
 		s.SetIPFilter(func(ip net.IP) bool {
-			return slices.Contains(filters.IPs, ip.String())
+			return core.Contains(filters.IPs, ip.String())
 		})
 	}
 
diff --git a/scripts/README.md b/scripts/README.md
index efcef154..eeb8c25d 100644
--- a/scripts/README.md
+++ b/scripts/README.md
@@ -1,3 +1,11 @@
+## Versions
+
+[Go 1.20](https://go.dev/doc/go1.20) is last version with support Windows 7 and macOS 10.13.
+Go 1.21 support only Windows 10 and macOS 10.15.
+
+So we will set `go 1.20` (minimum version) inside `go.mod` file. And will use env `GOTOOLCHAIN=go1.20.14` for building
+`win32` and `mac_amd64` binaries. All other binaries will use latest go version.
+
 ## Build
 
 - UPX-3.96 pack broken bin for `linux_mipsel`
diff --git a/scripts/build.cmd b/scripts/build.cmd
index 54565b2d..4a54039d 100644
--- a/scripts/build.cmd
+++ b/scripts/build.cmd
@@ -1,15 +1,18 @@
 @ECHO OFF
 
+@SET GOTOOLCHAIN=
 @SET GOOS=windows
 @SET GOARCH=amd64
 @SET FILENAME=go2rtc_win64.zip
 go build -ldflags "-s -w" -trimpath && 7z a -mx9 -sdel %FILENAME% go2rtc.exe
 
+@SET GOTOOLCHAIN=go1.20.14
 @SET GOOS=windows
 @SET GOARCH=386
 @SET FILENAME=go2rtc_win32.zip
 go build -ldflags "-s -w" -trimpath && 7z a -mx9 -sdel %FILENAME% go2rtc.exe
 
+@SET GOTOOLCHAIN=
 @SET GOOS=windows
 @SET GOARCH=arm64
 @SET FILENAME=go2rtc_win_arm64.zip
@@ -47,11 +50,13 @@ go build -ldflags "-s -w" -trimpath -o %FILENAME% && upx %FILENAME%
 @SET FILENAME=go2rtc_linux_mipsel
 go build -ldflags "-s -w" -trimpath -o %FILENAME% && upx %FILENAME%
 
+@SET GOTOOLCHAIN=go1.20.14
 @SET GOOS=darwin
 @SET GOARCH=amd64
 @SET FILENAME=go2rtc_mac_amd64.zip
 go build -ldflags "-s -w" -trimpath && 7z a -mx9 -sdel %FILENAME% go2rtc
 
+@SET GOTOOLCHAIN=
 @SET GOOS=darwin
 @SET GOARCH=arm64
 @SET FILENAME=go2rtc_mac_arm64.zip