diff --git a/src/pkg/net/fd.go b/src/pkg/net/fd.go
index 5adaf1d..5ec9184 100644
--- a/src/pkg/net/fd.go
+++ b/src/pkg/net/fd.go
@@ -606,3 +606,7 @@
 
 	return os.NewFile(ns, fd.sysfile.Name()), nil
 }
+
+func closesocket(s int) (errno int) {
+	return syscall.Close(s)
+}