diff --git a/keywordfuncs_bsd.go b/keywordfuncs_bsd.go
index 6114109..5b49c90 100644
--- a/keywordfuncs_bsd.go
+++ b/keywordfuncs_bsd.go
@@ -1,3 +1,4 @@
+//go:build darwin || freebsd || netbsd || openbsd
 // +build darwin freebsd netbsd openbsd
 
 package mtree
diff --git a/keywordfuncs_unsupported.go b/keywordfuncs_unsupported.go
index 1284895..3854d35 100644
--- a/keywordfuncs_unsupported.go
+++ b/keywordfuncs_unsupported.go
@@ -1,3 +1,4 @@
+//go:build !linux && !darwin && !freebsd && !netbsd && !openbsd
 // +build !linux,!darwin,!freebsd,!netbsd,!openbsd
 
 package mtree
diff --git a/lchtimes_unix.go b/lchtimes_unix.go
index 7cb5300..21b781b 100644
--- a/lchtimes_unix.go
+++ b/lchtimes_unix.go
@@ -1,3 +1,4 @@
+//go:build darwin || dragonfly || freebsd || openbsd || linux || netbsd || solaris
 // +build darwin dragonfly freebsd openbsd linux netbsd solaris
 
 package mtree
diff --git a/lchtimes_unsupported.go b/lchtimes_unsupported.go
index fac0532..7f54b89 100644
--- a/lchtimes_unsupported.go
+++ b/lchtimes_unsupported.go
@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package mtree
diff --git a/stat_unix.go b/stat_unix.go
index 9b87eb6..007dee2 100644
--- a/stat_unix.go
+++ b/stat_unix.go
@@ -1,3 +1,4 @@
+//go:build !windows
 // +build !windows
 
 package mtree
diff --git a/stat_windows.go b/stat_windows.go
index 34eb28e..cfd770b 100644
--- a/stat_windows.go
+++ b/stat_windows.go
@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package mtree
diff --git a/updatefuncs_linux.go b/updatefuncs_linux.go
index b7d7e83..d31ca41 100644
--- a/updatefuncs_linux.go
+++ b/updatefuncs_linux.go
@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package mtree
diff --git a/updatefuncs_unsupported.go b/updatefuncs_unsupported.go
index 9fc70e4..00d21fa 100644
--- a/updatefuncs_unsupported.go
+++ b/updatefuncs_unsupported.go
@@ -1,3 +1,4 @@
+//go:build !linux
 // +build !linux
 
 package mtree
diff --git a/xattr/xattr_test.go b/xattr/xattr_test.go
index c5d7923..668fac3 100644
--- a/xattr/xattr_test.go
+++ b/xattr/xattr_test.go
@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package xattr
diff --git a/xattr/xattr_unsupported.go b/xattr/xattr_unsupported.go
index 2ceda58..d83a799 100644
--- a/xattr/xattr_unsupported.go
+++ b/xattr/xattr_unsupported.go
@@ -1,3 +1,4 @@
+//go:build !linux
 // +build !linux
 
 package xattr
diff --git a/xattr/xattr_unsupported_test.go b/xattr/xattr_unsupported_test.go
index b4e32d5..7df2971 100644
--- a/xattr/xattr_unsupported_test.go
+++ b/xattr/xattr_unsupported_test.go
@@ -1,3 +1,4 @@
+//go:build !linux
 // +build !linux
 
 package xattr