diff --git a/lif/defs_solaris.go b/lif/defs_solaris.go
index d76f6a6..e85f503 100644
--- a/lif/defs_solaris.go
+++ b/lif/defs_solaris.go
@@ -65,9 +65,3 @@
 type lifconf C.struct_lifconf
 
 type lifIfinfoReq C.struct_lif_ifinfo_req
-
-const (
-	sysIFT_IPV4 = C.IFT_IPV4
-	sysIFT_IPV6 = C.IFT_IPV6
-	sysIFT_6TO4 = C.IFT_6TO4
-)
diff --git a/lif/link.go b/lif/link.go
index f1af130..428bffc 100644
--- a/lif/link.go
+++ b/lif/link.go
@@ -7,7 +7,11 @@
 
 package lif
 
-import "unsafe"
+import (
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
 
 // A Link represents logical data link information.
 //
@@ -43,7 +47,7 @@
 		ll.MTU = int(nativeEndian.Uint32(lifr.Lifru[:4]))
 	}
 	switch ll.Type {
-	case sysIFT_IPV4, sysIFT_IPV6, sysIFT_6TO4:
+	case unix.IFT_IPV4, unix.IFT_IPV6, unix.IFT_6TO4:
 	default:
 		ioc = int64(sysSIOCGLIFHWADDR)
 		if err := ioctl(s, uintptr(ioc), unsafe.Pointer(&lifr)); err == nil {
diff --git a/lif/zsys_solaris_amd64.go b/lif/zsys_solaris_amd64.go
index 6e7c982..2c94acf 100644
--- a/lif/zsys_solaris_amd64.go
+++ b/lif/zsys_solaris_amd64.go
@@ -77,9 +77,3 @@
 	Reachretrans uint32
 	Maxmtu       uint32
 }
-
-const (
-	sysIFT_IPV4 = 0xc8
-	sysIFT_IPV6 = 0xc9
-	sysIFT_6TO4 = 0xca
-)