diff --git a/src/pkg/net/sendfile_freebsd.go b/src/pkg/net/sendfile_freebsd.go
index dc5b767..42fe799 100644
--- a/src/pkg/net/sendfile_freebsd.go
+++ b/src/pkg/net/sendfile_freebsd.go
@@ -58,12 +58,10 @@
 		return 0, err, false
 	}
 
-	c.wio.Lock()
-	defer c.wio.Unlock()
-	if err := c.incref(false); err != nil {
+	if err := c.writeLock(); err != nil {
 		return 0, err, true
 	}
-	defer c.decref()
+	defer c.writeUnlock()
 
 	dst := c.sysfd
 	src := int(f.Fd())