diff --git a/unix/syscall_netbsd.go b/unix/syscall_netbsd.go
index b7aa28b6..e1a3baa2 100644
--- a/unix/syscall_netbsd.go
+++ b/unix/syscall_netbsd.go
@@ -233,6 +233,7 @@ func Uname(uname *Utsname) error {
 //sys	Dup(fd int) (nfd int, err error)
 //sys	Dup2(from int, to int) (err error)
 //sys	Exit(code int)
+//sys	Fadvise(fd int, offset int64, length int64, advice int) (err error) = SYS_POSIX_FADVISE
 //sys	Fchdir(fd int) (err error)
 //sys	Fchflags(fd int, flags int) (err error)
 //sys	Fchmod(fd int, mode uint32) (err error)
@@ -322,7 +323,6 @@ func Uname(uname *Utsname) error {
 // __msync13
 // __ntp_gettime30
 // __posix_chown
-// __posix_fadvise50
 // __posix_fchown
 // __posix_lchown
 // __posix_rename
diff --git a/unix/types_netbsd.go b/unix/types_netbsd.go
index 10aa9b3a..1494aafc 100644
--- a/unix/types_netbsd.go
+++ b/unix/types_netbsd.go
@@ -118,6 +118,17 @@ const (
 	PathMax = C.PATH_MAX
 )
 
+// Advice to Fadvise
+
+const (
+	FADV_NORMAL     = C.POSIX_FADV_NORMAL
+	FADV_RANDOM     = C.POSIX_FADV_RANDOM
+	FADV_SEQUENTIAL = C.POSIX_FADV_SEQUENTIAL
+	FADV_WILLNEED   = C.POSIX_FADV_WILLNEED
+	FADV_DONTNEED   = C.POSIX_FADV_DONTNEED
+	FADV_NOREUSE    = C.POSIX_FADV_NOREUSE
+)
+
 // Sockets
 
 type RawSockaddrInet4 C.struct_sockaddr_in
diff --git a/unix/zsyscall_netbsd_386.go b/unix/zsyscall_netbsd_386.go
index ec274aa1..fb4b9627 100644
--- a/unix/zsyscall_netbsd_386.go
+++ b/unix/zsyscall_netbsd_386.go
@@ -571,6 +571,16 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall9(SYS_POSIX_FADVISE, uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), 0, uintptr(length), uintptr(length>>32), uintptr(advice), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchdir(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
 	if e1 != 0 {
diff --git a/unix/zsyscall_netbsd_amd64.go b/unix/zsyscall_netbsd_amd64.go
index 35eb6fc5..beac82ef 100644
--- a/unix/zsyscall_netbsd_amd64.go
+++ b/unix/zsyscall_netbsd_amd64.go
@@ -571,6 +571,16 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall6(SYS_POSIX_FADVISE, uintptr(fd), 0, uintptr(offset), 0, uintptr(length), uintptr(advice))
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchdir(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
 	if e1 != 0 {
diff --git a/unix/zsyscall_netbsd_arm.go b/unix/zsyscall_netbsd_arm.go
index d8bcfa8b..7bd5f60b 100644
--- a/unix/zsyscall_netbsd_arm.go
+++ b/unix/zsyscall_netbsd_arm.go
@@ -571,6 +571,16 @@ func Exit(code int) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func Fadvise(fd int, offset int64, length int64, advice int) (err error) {
+	_, _, e1 := Syscall9(SYS_POSIX_FADVISE, uintptr(fd), 0, uintptr(offset), uintptr(offset>>32), 0, uintptr(length), uintptr(length>>32), uintptr(advice), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Fchdir(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_FCHDIR, uintptr(fd), 0, 0)
 	if e1 != 0 {
diff --git a/unix/ztypes_netbsd_386.go b/unix/ztypes_netbsd_386.go
index da70faa8..4b86fb2b 100644
--- a/unix/ztypes_netbsd_386.go
+++ b/unix/ztypes_netbsd_386.go
@@ -103,6 +103,15 @@ const (
 	PathMax = 0x400
 )
 
+const (
+	FADV_NORMAL     = 0x0
+	FADV_RANDOM     = 0x1
+	FADV_SEQUENTIAL = 0x2
+	FADV_WILLNEED   = 0x3
+	FADV_DONTNEED   = 0x4
+	FADV_NOREUSE    = 0x5
+)
+
 type RawSockaddrInet4 struct {
 	Len    uint8
 	Family uint8
diff --git a/unix/ztypes_netbsd_amd64.go b/unix/ztypes_netbsd_amd64.go
index 0963ab8c..9048a509 100644
--- a/unix/ztypes_netbsd_amd64.go
+++ b/unix/ztypes_netbsd_amd64.go
@@ -107,6 +107,15 @@ const (
 	PathMax = 0x400
 )
 
+const (
+	FADV_NORMAL     = 0x0
+	FADV_RANDOM     = 0x1
+	FADV_SEQUENTIAL = 0x2
+	FADV_WILLNEED   = 0x3
+	FADV_DONTNEED   = 0x4
+	FADV_NOREUSE    = 0x5
+)
+
 type RawSockaddrInet4 struct {
 	Len    uint8
 	Family uint8
diff --git a/unix/ztypes_netbsd_arm.go b/unix/ztypes_netbsd_arm.go
index 211f6419..00525e7b 100644
--- a/unix/ztypes_netbsd_arm.go
+++ b/unix/ztypes_netbsd_arm.go
@@ -108,6 +108,15 @@ const (
 	PathMax = 0x400
 )
 
+const (
+	FADV_NORMAL     = 0x0
+	FADV_RANDOM     = 0x1
+	FADV_SEQUENTIAL = 0x2
+	FADV_WILLNEED   = 0x3
+	FADV_DONTNEED   = 0x4
+	FADV_NOREUSE    = 0x5
+)
+
 type RawSockaddrInet4 struct {
 	Len    uint8
 	Family uint8