diff --git a/plat/msdos386/libsys/build.lua b/plat/msdos386/libsys/build.lua
index c2ae13f52..2725c0f70 100644
--- a/plat/msdos386/libsys/build.lua
+++ b/plat/msdos386/libsys/build.lua
@@ -1,6 +1,7 @@
 acklibrary {
     name = "lib",
     srcs = {
+		"./rename.s",
 --		"./brk.c",
 --		"./close.s",
 --		"./creat.c",
diff --git a/plat/msdos86/libsys/build.lua b/plat/msdos86/libsys/build.lua
index e7d9b8fc7..58bf3e6e5 100644
--- a/plat/msdos86/libsys/build.lua
+++ b/plat/msdos86/libsys/build.lua
@@ -6,6 +6,7 @@ acklibrary {
 		"./getpid.s",
 		"./_hol0.s",
 		"./isatty.s",
+		"./rename.s",
 		"./sys_exists.s",
 		"./sys_getdate.s",
 		"./sys_gettime.s",
diff --git a/plat/msdos86/libsys/rename.s b/plat/msdos86/libsys/rename.s
new file mode 100644
index 000000000..edb14266b
--- /dev/null
+++ b/plat/msdos86/libsys/rename.s
@@ -0,0 +1,26 @@
+#
+! $Source$
+! $State$
+! $Revision$
+
+! Declare segments (the order is important).
+
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+.sect .text
+
+! Rename a file.
+
+.define _rename
+_rename:
+	mov bx, sp
+	push di
+	mov dx, 2(bx)
+	mov di, 4(bx)
+	movb ah, 0x56
+	int 0x21
+	pop di
+	jmp .sys_zret