diff --git a/modules/src/system/open.c b/modules/src/system/open.c
index cf24f3206..1433cea9f 100644
--- a/modules/src/system/open.c
+++ b/modules/src/system/open.c
@@ -4,6 +4,7 @@
  */
 /* $Id$ */
 
+#include <unistd.h>
 #include "system.h"
 
 extern File *_get_entry();
@@ -16,7 +17,6 @@ sys_open(path, flag, filep)
 {
 	register int fd;
 	register File *fp;
-	long lseek();
 
 	if ((fp = _get_entry()) == (File *)0)
 		return 0;
diff --git a/modules/src/system/seek.c b/modules/src/system/seek.c
index e4d1f8580..97749ae12 100644
--- a/modules/src/system/seek.c
+++ b/modules/src/system/seek.c
@@ -4,10 +4,9 @@
  */
 /* $Id$ */
 
+#include <unistd.h>
 #include "system.h"
 
-long lseek();
-
 int
 sys_seek(fp, off, whence, poff)
 	File *fp;