--- /usr/src/bin/cat/cat.c	2016-07-22 16:42:11.671288000 +0300
+++ cat.c	2016-09-13 11:14:08.858013000 +0300
@@ -63,6 +63,8 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <wchar.h>
+#include <wctype.h>
 
 static int bflag, eflag, lflag, nflag, sflag, tflag, vflag;
 static int rval;
@@ -205,6 +207,7 @@
 cook_cat(FILE *fp)
 {
 	int ch, gobble, line, prev;
+	wint_t wch;
 
 	/* Reset EOF condition on stdin. */
 	if (fp == stdin && feof(stdin))
@@ -237,18 +240,34 @@
 				continue;
 			}
 		} else if (vflag) {
-			if (!isascii(ch) && !isprint(ch)) {
+			ungetc(ch, fp);
+			if ((wch = getwc(fp)) == WEOF) {
+				if (ferror(fp) && errno == EILSEQ) {
+					clearerr(fp);
+					if ((ch = getc(fp)) == EOF)
+						break;
+					wch = ch;
+					goto ilseq;
+				} else
+					break;
+			}
+			if (!iswascii(wch) && !iswprint(wch)) {
+ilseq:
 				if (putchar('M') == EOF || putchar('-') == EOF)
 					break;
-				ch = toascii(ch);
+				wch = toascii(wch);
 			}
-			if (iscntrl(ch)) {
+			if (iswcntrl(wch)) {
+				ch = toascii(wch);
 				if (putchar('^') == EOF ||
 				    putchar(ch == '\177' ? '?' :
 				    ch | 0100) == EOF)
 					break;
 				continue;
 			}
+			if (putwchar(wch) == WEOF)
+				break;
+			continue;
 		}
 		if (putchar(ch) == EOF)
 			break;