diff --git a/appl/telnet/libtelnet/auth.c b/appl/telnet/libtelnet/auth.c
index 3cb9a2421..84a036a0a 100644
--- a/appl/telnet/libtelnet/auth.c
+++ b/appl/telnet/libtelnet/auth.c
@@ -60,18 +60,16 @@ RCSID("$Id$");
 
 #if	defined(AUTHENTICATION)
 #include <stdio.h>
+#ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
+#endif
 #include <signal.h>
 #define	AUTH_NAMES
+#ifdef HAVE_ARPA_TELNET_H
 #include <arpa/telnet.h>
-#ifdef	__STDC__
+#endif
 #include <stdlib.h>
-#endif
-#ifdef	NO_STRING_H
-#include <strings.h>
-#else
 #include <string.h>
-#endif
 
 #include "encrypt.h"
 #include "auth.h"
diff --git a/appl/telnet/libtelnet/kerberos.c b/appl/telnet/libtelnet/kerberos.c
index 06ec7eef0..2aff372bb 100644
--- a/appl/telnet/libtelnet/kerberos.c
+++ b/appl/telnet/libtelnet/kerberos.c
@@ -62,20 +62,18 @@
 RCSID("$Id$");
 
 #ifdef	KRB4
+#ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
+#endif
+#ifdef HAVE_ARPA_TELNET_H
 #include <arpa/telnet.h>
+#endif
 #include <stdio.h>
 #include <des.h>	/* BSD wont include this in krb.h, so we do it here */
 #include <krb.h>
 #include <pwd.h>
-#ifdef	__STDC__
 #include <stdlib.h>
-#endif
-#ifdef	NO_STRING_H
-#include <strings.h>
-#else
 #include <string.h>
-#endif
 
 #include "encrypt.h"
 #include "auth.h"
diff --git a/appl/telnet/libtelnet/rsaencpwd.c b/appl/telnet/libtelnet/rsaencpwd.c
index 1b1e573f2..459883f0e 100644
--- a/appl/telnet/libtelnet/rsaencpwd.c
+++ b/appl/telnet/libtelnet/rsaencpwd.c
@@ -73,18 +73,14 @@ RCSID("$Id$");
  */
 
 #include <sys/types.h>
+#ifdef HAVE_ARPA_TELNET_H
 #include <arpa/telnet.h>
+#endif
 #include <pwd.h>
 #include <stdio.h>
 
-#ifdef	__STDC__
 #include <stdlib.h>
-#endif
-#ifdef	NO_STRING_H
-#include <strings.h>
-#else
 #include <string.h>
-#endif
 
 #include "encrypt.h"
 #include "auth.h"
diff --git a/appl/telnet/libtelnet/spx.c b/appl/telnet/libtelnet/spx.c
index 896edc62f..c28c2566f 100644
--- a/appl/telnet/libtelnet/spx.c
+++ b/appl/telnet/libtelnet/spx.c
@@ -72,18 +72,16 @@ RCSID("$Id$");
  *
  */
 
+#ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
+#endif
+#ifdef HAVE_ARPA_TELNET_H
 #include <arpa/telnet.h>
+#endif
 #include <stdio.h>
 #include "gssapi_defs.h"
-#ifdef	__STDC__
 #include <stdlib.h>
-#endif
-#ifdef	NO_STRING_H
-#include <strings.h>
-#else
 #include <string.h>
-#endif
 
 #include <pwd.h>
 #include "encrypt.h"