diff --git a/mach/sun3/libsys/LIST b/mach/sun3/libsys/LIST
index bacc0aca5..c2821c3c6 100644
--- a/mach/sun3/libsys/LIST
+++ b/mach/sun3/libsys/LIST
@@ -19,6 +19,7 @@ connect.s
 creat.s
 _creat.s
 dup.s
+_dup.s
 dup2.s
 _dup2.s
 execl.c
diff --git a/mach/sun3/libsys/_dup.s b/mach/sun3/libsys/_dup.s
new file mode 100644
index 000000000..b2f4d6fc7
--- /dev/null
+++ b/mach/sun3/libsys/_dup.s
@@ -0,0 +1,4 @@
+#include "syscall.h"
+.sect .text; .sect .rom; .sect .data; .sect .bss; .sect .text
+.define __dup
+__dup: SYSTEM(SYS_dup)