Check HAVE_STRING_H.

src/libraries/libansi/memcpy.c

+#ifdef HAVE_STRING_H
 #include <string.h>
+#endif
+#include <sys/types.h>
 
 void *
 memcpy (void * s1, const void * s2, size_t n)

src/libraries/libansi/strerror.c

 /*
- * $Id: strerror.c,v 0.10 1993/10/10 12:01:57 ceder Exp $
+ * $Id: strerror.c,v 0.11 1993/10/12 23:40:40 ceder Exp $
  * Copyright (C) 1991  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -26,12 +26,14 @@
 ** strerror.c
 */
 
-static char *rcsid = "$Id: strerror.c,v 0.10 1993/10/10 12:01:57 ceder Exp $";
+static char *rcsid = "$Id: strerror.c,v 0.11 1993/10/12 23:40:40 ceder Exp $";
 #include "rcs.h"
 USE(rcsid);
 
 #include <stdio.h>
+#ifdef HAVE_STRING_H
 #include <string.h>
+#endif
 
 extern int sys_nerr;
 extern const char *sys_errlist[];