diff --git a/usr.sbin/i4b/isdndecode/main.c b/usr.sbin/i4b/isdndecode/main.c
index c4c9e7fe6c97..76afab109d47 100644
--- a/usr.sbin/i4b/isdndecode/main.c
+++ b/usr.sbin/i4b/isdndecode/main.c
@@ -36,6 +36,7 @@
  *---------------------------------------------------------------------------*/
 
 #include "decode.h"
+#include <unistd.h>
 
 unsigned char buf[BSIZE];
 FILE *Fout = NULL;
@@ -104,9 +105,6 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
-	extern int optind;
-	extern int opterr;
-	extern char *optarg;
 	char devicename[80];
 	char headerbuf[256];
 		
diff --git a/usr.sbin/i4b/isdntel/main.c b/usr.sbin/i4b/isdntel/main.c
index da5ec820c160..6bea96662703 100644
--- a/usr.sbin/i4b/isdntel/main.c
+++ b/usr.sbin/i4b/isdntel/main.c
@@ -37,6 +37,7 @@
 
 #define MAIN
 #include <locale.h>
+#include <unistd.h>
 #include "defs.h"
 #include "alias.h"
 
@@ -62,8 +63,6 @@ main(int argc, char **argv)
 	char *aliasfile = ALIASFILE;
 	int rrtimeout = REREADTIMEOUT;
 	
-	extern char *optarg;	
-
 	setlocale( LC_ALL, "");
 	
 	while ((i = getopt(argc, argv, "a:d:p:t:")) != -1)