diff --git a/src/core/debug.go b/src/core/debug.go
index 0fc08259..eb406798 100644
--- a/src/core/debug.go
+++ b/src/core/debug.go
@@ -1,3 +1,4 @@
+//go:build debug
 // +build debug
 
 package core
diff --git a/src/core/tcp_darwin.go b/src/core/tcp_darwin.go
index 6b85c621..2ea3abc8 100644
--- a/src/core/tcp_darwin.go
+++ b/src/core/tcp_darwin.go
@@ -1,3 +1,4 @@
+//go:build darwin
 // +build darwin
 
 package core
diff --git a/src/core/tcp_linux.go b/src/core/tcp_linux.go
index 558b4e56..e59c3121 100644
--- a/src/core/tcp_linux.go
+++ b/src/core/tcp_linux.go
@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package core
diff --git a/src/core/tcp_other.go b/src/core/tcp_other.go
index 97b81ed1..8dd76f28 100644
--- a/src/core/tcp_other.go
+++ b/src/core/tcp_other.go
@@ -1,3 +1,4 @@
+//go:build !darwin && !linux
 // +build !darwin,!linux
 
 package core
diff --git a/src/defaults/defaults_darwin.go b/src/defaults/defaults_darwin.go
index e16f398f..060ce814 100644
--- a/src/defaults/defaults_darwin.go
+++ b/src/defaults/defaults_darwin.go
@@ -1,3 +1,4 @@
+//go:build darwin
 // +build darwin
 
 package defaults
diff --git a/src/defaults/defaults_freebsd.go b/src/defaults/defaults_freebsd.go
index 6c3e1c60..84df48ad 100644
--- a/src/defaults/defaults_freebsd.go
+++ b/src/defaults/defaults_freebsd.go
@@ -1,3 +1,4 @@
+//go:build freebsd
 // +build freebsd
 
 package defaults
diff --git a/src/defaults/defaults_linux.go b/src/defaults/defaults_linux.go
index 95c7ae95..c7f5f119 100644
--- a/src/defaults/defaults_linux.go
+++ b/src/defaults/defaults_linux.go
@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package defaults
diff --git a/src/defaults/defaults_openbsd.go b/src/defaults/defaults_openbsd.go
index ef339546..0ec877ca 100644
--- a/src/defaults/defaults_openbsd.go
+++ b/src/defaults/defaults_openbsd.go
@@ -1,3 +1,4 @@
+//go:build openbsd
 // +build openbsd
 
 package defaults
diff --git a/src/defaults/defaults_other.go b/src/defaults/defaults_other.go
index d1417322..37637425 100644
--- a/src/defaults/defaults_other.go
+++ b/src/defaults/defaults_other.go
@@ -1,3 +1,4 @@
+//go:build !linux && !darwin && !windows && !openbsd && !freebsd
 // +build !linux,!darwin,!windows,!openbsd,!freebsd
 
 package defaults
diff --git a/src/defaults/defaults_windows.go b/src/defaults/defaults_windows.go
index e81d09cf..c1ea9689 100644
--- a/src/defaults/defaults_windows.go
+++ b/src/defaults/defaults_windows.go
@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package defaults
diff --git a/src/multicast/multicast_darwin.go b/src/multicast/multicast_darwin.go
index e7075c0a..7ad0c543 100644
--- a/src/multicast/multicast_darwin.go
+++ b/src/multicast/multicast_darwin.go
@@ -1,3 +1,4 @@
+//go:build darwin
 // +build darwin
 
 package multicast
diff --git a/src/multicast/multicast_other.go b/src/multicast/multicast_other.go
index dfcf625f..9977951c 100644
--- a/src/multicast/multicast_other.go
+++ b/src/multicast/multicast_other.go
@@ -1,3 +1,4 @@
+//go:build !linux && !darwin && !netbsd && !freebsd && !openbsd && !dragonflybsd && !windows
 // +build !linux,!darwin,!netbsd,!freebsd,!openbsd,!dragonflybsd,!windows
 
 package multicast
diff --git a/src/multicast/multicast_unix.go b/src/multicast/multicast_unix.go
index 1ff48b17..9c822fcf 100644
--- a/src/multicast/multicast_unix.go
+++ b/src/multicast/multicast_unix.go
@@ -1,3 +1,4 @@
+//go:build linux || netbsd || freebsd || openbsd || dragonflybsd
 // +build linux netbsd freebsd openbsd dragonflybsd
 
 package multicast
diff --git a/src/multicast/multicast_windows.go b/src/multicast/multicast_windows.go
index 3666faaa..515412a4 100644
--- a/src/multicast/multicast_windows.go
+++ b/src/multicast/multicast_windows.go
@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package multicast
diff --git a/src/tuntap/tun_bsd.go b/src/tuntap/tun_bsd.go
index 75158857..fe36266b 100644
--- a/src/tuntap/tun_bsd.go
+++ b/src/tuntap/tun_bsd.go
@@ -1,3 +1,4 @@
+//go:build openbsd || freebsd
 // +build openbsd freebsd
 
 package tuntap
diff --git a/src/tuntap/tun_darwin.go b/src/tuntap/tun_darwin.go
index 75938881..6f6e2528 100644
--- a/src/tuntap/tun_darwin.go
+++ b/src/tuntap/tun_darwin.go
@@ -1,3 +1,4 @@
+//go:build !mobile
 // +build !mobile
 
 package tuntap
diff --git a/src/tuntap/tun_linux.go b/src/tuntap/tun_linux.go
index 0a845368..f849c00f 100644
--- a/src/tuntap/tun_linux.go
+++ b/src/tuntap/tun_linux.go
@@ -1,3 +1,4 @@
+//go:build !mobile
 // +build !mobile
 
 package tuntap
diff --git a/src/tuntap/tun_other.go b/src/tuntap/tun_other.go
index c0321267..8ce24953 100644
--- a/src/tuntap/tun_other.go
+++ b/src/tuntap/tun_other.go
@@ -1,3 +1,4 @@
+//go:build !linux && !darwin && !windows && !openbsd && !freebsd && !mobile
 // +build !linux,!darwin,!windows,!openbsd,!freebsd,!mobile
 
 package tuntap
diff --git a/src/tuntap/tun_windows.go b/src/tuntap/tun_windows.go
index 7b7ee710..8dce7274 100644
--- a/src/tuntap/tun_windows.go
+++ b/src/tuntap/tun_windows.go
@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package tuntap