--- a/src/charset.c
+++ b/src/charset.c
@@ -9,12 +9,10 @@
 
 #include "vim.h"
 
-#ifdef FEAT_MBYTE
-# if defined(HAVE_WCHAR_H)
-#  include <wchar.h>	    /* for towupper() and towlower() */
-# endif
+#if defined(HAVE_WCHAR_H)
+# include <wchar.h>	    /* for towupper() and towlower() */
+#endif
 static int win_nolbr_chartabsize(win_T *wp, char_u *s, colnr_T col, int *headp);
-#endif
 
 static unsigned nr2hex(unsigned c);
 
@@ -109,7 +107,6 @@ buf_init_chartab(
 #endif
 	while (c < 256)
 	{
-#ifdef FEAT_MBYTE
 	    /* UTF-8: bytes 0xa0 - 0xff are printable (latin1) */
 	    if (enc_utf8 && c >= 0xa0)
 		g_chartab[c++] = CT_PRINT_CHAR + 1;
@@ -120,26 +117,22 @@ buf_init_chartab(
 	    else if (enc_dbcs != 0 && MB_BYTE2LEN(c) == 2)
 		g_chartab[c++] = CT_PRINT_CHAR + 2;
 	    else
-#endif
 		/* the rest is unprintable by default */
 		g_chartab[c++] = (dy_flags & DY_UHEX) ? 4 : 2;
 	}
 
-#ifdef FEAT_MBYTE
 	/* Assume that every multi-byte char is a filename character. */
 	for (c = 1; c < 256; ++c)
 	    if ((enc_dbcs != 0 && MB_BYTE2LEN(c) > 1)
 		    || (enc_dbcs == DBCS_JPNU && c == 0x8e)
 		    || (enc_utf8 && c >= 0xa0))
 		g_chartab[c] |= CT_FNAME_CHAR;
-#endif
     }
 
     /*
      * Init word char flags all to FALSE
      */
     vim_memset(buf->b_chartab, 0, (size_t)32);
-#ifdef FEAT_MBYTE
     if (enc_dbcs != 0)
 	for (c = 0; c < 256; ++c)
 	{
@@ -147,7 +140,6 @@ buf_init_chartab(
 	    if (MB_BYTE2LEN(c) == 2)
 		SET_CHARTAB(buf, c);
 	}
-#endif
 
 #ifdef FEAT_LISP
     /*
@@ -184,11 +176,9 @@ buf_init_chartab(
 	    if (VIM_ISDIGIT(*p))
 		c = getdigits(&p);
 	    else
-#ifdef FEAT_MBYTE
 		 if (has_mbyte)
 		c = mb_ptr2char_adv(&p);
 	    else
-#endif
 		c = *p++;
 	    c2 = -1;
 	    if (*p == '-' && p[1] != NUL)
@@ -197,11 +187,9 @@ buf_init_chartab(
 		if (VIM_ISDIGIT(*p))
 		    c2 = getdigits(&p);
 		else
-#ifdef FEAT_MBYTE
 		     if (has_mbyte)
 		    c2 = mb_ptr2char_adv(&p);
 		else
-#endif
 		    c2 = *p++;
 	    }
 	    if (c <= 0 || c >= 256 || (c2 < c && c2 != -1) || c2 >= 256
@@ -253,13 +241,9 @@ buf_init_chartab(
 				    || (p_altkeymap
 					&& (F_isalpha(c) || F_isdigit(c)))
 #endif
-			    )
-#ifdef FEAT_MBYTE
-				/* For double-byte we keep the cell width, so
-				 * that we can detect it from the first byte. */
-				&& !(enc_dbcs && MB_BYTE2LEN(c) == 2)
-#endif
-			   )
+				// For double-byte we keep the cell width, so
+				// that we can detect it from the first byte.
+			    ) && !(enc_dbcs && MB_BYTE2LEN(c) == 2))
 			{
 			    if (tilde)
 			    {
@@ -322,12 +306,10 @@ trans_characters(
     room = bufsize - len;
     while (*buf != 0)
     {
-# ifdef FEAT_MBYTE
 	/* Assume a multi-byte character doesn't need translation. */
 	if (has_mbyte && (trs_len = (*mb_ptr2len)(buf)) > 1)
 	    len -= trs_len;
 	else
-# endif
 	{
 	    trs = transchar_byte(*buf);
 	    trs_len = (int)STRLEN(trs);
@@ -356,12 +338,9 @@ transstr(char_u *s)
 {
     char_u	*res;
     char_u	*p;
-#ifdef FEAT_MBYTE
     int		l, len, c;
     char_u	hexbuf[11];
-#endif
 
-#ifdef FEAT_MBYTE
     if (has_mbyte)
     {
 	/* Compute the length of the result, taking account of unprintable
@@ -394,7 +373,6 @@ transstr(char_u *s)
 	res = alloc((unsigned)(len + 1));
     }
     else
-#endif
 	res = alloc((unsigned)(vim_strsize(s) + 1));
     if (res != NULL)
     {
@@ -402,7 +380,6 @@ transstr(char_u *s)
 	p = s;
 	while (*p != NUL)
 	{
-#ifdef FEAT_MBYTE
 	    if (has_mbyte && (l = (*mb_ptr2len)(p)) > 1)
 	    {
 		c = (*mb_ptr2char)(p);
@@ -413,7 +390,6 @@ transstr(char_u *s)
 		p += l;
 	    }
 	    else
-#endif
 		STRCAT(res, transchar_byte(*p++));
 	}
     }
@@ -468,7 +444,6 @@ str_foldcase(
     i = 0;
     while (STR_CHAR(i) != NUL)
     {
-#ifdef FEAT_MBYTE
 	if (enc_utf8 || (has_mbyte && MB_BYTE2LEN(STR_CHAR(i)) > 1))
 	{
 	    if (enc_utf8)
@@ -520,7 +495,6 @@ str_foldcase(
 	    i += (*mb_ptr2len)(STR_PTR(i));
 	}
 	else
-#endif
 	{
 	    if (buf == NULL)
 		GA_CHAR(i) = TOLOWER_LOC(GA_CHAR(i));
@@ -580,7 +554,6 @@ transchar(int c)
     return transchar_buf;
 }
 
-#if defined(FEAT_MBYTE) || defined(PROTO)
 /*
  * Like transchar(), but called with a byte instead of a character.  Checks
  * for an illegal UTF-8 byte.
@@ -595,7 +568,6 @@ transchar_byte(int c)
     }
     return transchar(c);
 }
-#endif
 
 /*
  * Convert non-printable character to two or more printable characters in
@@ -632,12 +604,10 @@ transchar_nonprint(char_u *buf, int c)
 
 	buf[2] = NUL;
     }
-#ifdef FEAT_MBYTE
     else if (enc_utf8 && c >= 0x80)
     {
 	transchar_hex(buf, c);
     }
-#endif
 #ifndef EBCDIC
     else if (c >= ' ' + 0x80 && c <= '~' + 0x80)    /* 0xa0 - 0xfe */
     {
@@ -675,13 +645,11 @@ transchar_hex(char_u *buf, int c)
     int		i = 0;
 
     buf[0] = '<';
-#ifdef FEAT_MBYTE
     if (c > 255)
     {
 	buf[++i] = nr2hex((unsigned)c >> 12);
 	buf[++i] = nr2hex((unsigned)c >> 8);
     }
-#endif
     buf[++i] = nr2hex((unsigned)c >> 4);
     buf[++i] = nr2hex((unsigned)c);
     buf[++i] = '>';
@@ -712,10 +680,8 @@ nr2hex(unsigned c)
     int
 byte2cells(int b)
 {
-#ifdef FEAT_MBYTE
     if (enc_utf8 && b >= 0x80)
 	return 0;
-#endif
     return (g_chartab[b] & CT_CELL_MASK);
 }
 
@@ -729,7 +695,6 @@ char2cells(int c)
 {
     if (IS_SPECIAL(c))
 	return char2cells(K_SECOND(c)) + 2;
-#ifdef FEAT_MBYTE
     if (c >= 0x80)
     {
 	/* UTF-8: above 0x80 need to check the value */
@@ -744,7 +709,6 @@ char2cells(int c)
 	    return 2;
 	}
     }
-#endif
     return (g_chartab[c & 0xff] & CT_CELL_MASK);
 }
 
@@ -755,12 +719,10 @@ char2cells(int c)
     int
 ptr2cells(char_u *p)
 {
-#ifdef FEAT_MBYTE
     /* For UTF-8 we need to look at more bytes if the first byte is >= 0x80. */
     if (enc_utf8 && *p >= 0x80)
 	return utf_ptr2cells(p);
     /* For DBCS we can tell the cell count from the first byte. */
-#endif
     return (g_chartab[*p] & CT_CELL_MASK);
 }
 
@@ -784,8 +746,6 @@ vim_strnsize(char_u *s, int len)
     int		size = 0;
 
     while (*s != NUL && --len >= 0)
-    {
-#ifdef FEAT_MBYTE
 	if (has_mbyte)
 	{
 	    int	    l = (*mb_ptr2len)(s);
@@ -795,9 +755,8 @@ vim_strnsize(char_u *s, int len)
 	    len -= l - 1;
 	}
 	else
-#endif
 	    size += byte2cells(*s++);
-    }
+
     return size;
 }
 
@@ -907,12 +866,10 @@ vim_iswordc_buf(int c, buf_T *buf)
 {
     if (c >= 0x100)
     {
-#ifdef FEAT_MBYTE
 	if (enc_dbcs != 0)
 	    return dbcs_class((unsigned)c >> 8, (unsigned)(c & 0xff)) >= 2;
 	if (enc_utf8)
 	    return utf_class_buf(c, buf) >= 2;
-#endif
 	return FALSE;
     }
     return (c > 0 && GET_CHARTAB(buf, c) != 0);
@@ -932,10 +889,8 @@ vim_iswordp_buf(char_u *p, buf_T *buf)
 {
     int	c = *p;
 
-#ifdef FEAT_MBYTE
     if (has_mbyte && MB_BYTE2LEN(c) > 1)
 	c = (*mb_ptr2char)(p);
-#endif
     return vim_iswordc_buf(c, buf);
 }
 
@@ -973,10 +928,8 @@ vim_isfilec_or_wc(int c)
     int
 vim_isprintc(int c)
 {
-#ifdef FEAT_MBYTE
     if (enc_utf8 && c >= 0x100)
 	return utf_printable(c);
-#endif
     return (c >= 0x100 || (c > 0 && (g_chartab[c] & CT_PRINT_CHAR)));
 }
 
@@ -987,12 +940,10 @@ vim_isprintc(int c)
     int
 vim_isprintc_strict(int c)
 {
-#ifdef FEAT_MBYTE
     if (enc_dbcs != 0 && c < 0x100 && MB_BYTE2LEN(c) > 1)
 	return FALSE;
     if (enc_utf8 && c >= 0x100)
 	return utf_printable(c);
-#endif
     return (c >= 0x100 || (c > 0 && (g_chartab[c] & CT_PRINT_CHAR)));
 }
 
@@ -1009,10 +960,8 @@ lbr_chartabsize(
     if (!curwin->w_p_lbr && *p_sbr == NUL && !curwin->w_p_bri)
     {
 #endif
-#ifdef FEAT_MBYTE
 	if (curwin->w_p_wrap)
 	    return win_nolbr_chartabsize(curwin, s, col, NULL);
-#endif
 	RET_WIN_BUF_CHARTABSIZE(curwin, curbuf, s, col)
 #ifdef FEAT_LINEBREAK
     }
@@ -1058,11 +1007,7 @@ win_lbr_chartabsize(
     colnr_T	col_adj = 0; /* col + screen size of tab */
     colnr_T	colmax;
     int		added;
-# ifdef FEAT_MBYTE
     int		mb_added = 0;
-# else
-#  define mb_added 0
-# endif
     int		numberextra;
     char_u	*ps;
     int		tab_corr = (*s == TAB);
@@ -1074,10 +1019,8 @@ win_lbr_chartabsize(
     if (!wp->w_p_lbr && !wp->w_p_bri && *p_sbr == NUL)
 #endif
     {
-#ifdef FEAT_MBYTE
 	if (wp->w_p_wrap)
 	    return win_nolbr_chartabsize(wp, s, col, headp);
-#endif
 	RET_WIN_BUF_CHARTABSIZE(wp, wp->w_buffer, s, col)
     }
 
@@ -1135,14 +1078,12 @@ win_lbr_chartabsize(
 	    }
 	}
     }
-# ifdef FEAT_MBYTE
     else if (has_mbyte && size == 2 && MB_BYTE2LEN(*s) > 1
 				    && wp->w_p_wrap && in_win_border(wp, col))
     {
 	++size;		/* Count the ">" in the last column. */
 	mb_added = 1;
     }
-# endif
 
     /*
      * May have to add something for 'breakindent' and/or 'showbreak'
@@ -1210,7 +1151,6 @@ win_lbr_chartabsize(
 #endif
 }
 
-#if defined(FEAT_MBYTE) || defined(PROTO)
 /*
  * Like win_lbr_chartabsize(), except that we know 'linebreak' is off and
  * 'wrap' is on.  This means we need to check for a double-byte character that
@@ -1269,7 +1209,6 @@ in_win_border(win_T *wp, colnr_T vcol)
 	return FALSE;
     return ((vcol - width1) % width2 == width2 - 1);
 }
-#endif /* FEAT_MBYTE */
 
 /*
  * Get virtual column number of pos.
@@ -1310,11 +1249,9 @@ getvcol(
 	if (*ptr == NUL)
 	    pos->col = 0;
 	posptr = ptr + pos->col;
-#ifdef FEAT_MBYTE
 	if (has_mbyte)
 	    /* always start on the first byte */
 	    posptr -= (*mb_head_off)(line, posptr);
-#endif
     }
 
     /*
@@ -1329,14 +1266,10 @@ getvcol(
 #endif
        )
     {
-#ifndef FEAT_MBYTE
 	head = 0;
-#endif
 	for (;;)
 	{
-#ifdef FEAT_MBYTE
 	    head = 0;
-#endif
 	    c = *ptr;
 	    /* make sure we don't go past the end of the line */
 	    if (c == NUL)
@@ -1353,7 +1286,6 @@ getvcol(
 #endif
 	    else
 	    {
-#ifdef FEAT_MBYTE
 		if (has_mbyte)
 		{
 		    /* For utf-8, if the byte is >= 0x80, need to look at
@@ -1374,7 +1306,6 @@ getvcol(
 		    }
 		}
 		else
-#endif
 		    incr = g_chartab[c] & CT_CELL_MASK;
 	    }
 
@@ -1460,9 +1391,7 @@ getvvcol(
     colnr_T	col;
     colnr_T	coladd;
     colnr_T	endadd;
-# ifdef FEAT_MBYTE
     char_u	*ptr;
-# endif
 
     if (virtual_active())
     {
@@ -1471,7 +1400,6 @@ getvvcol(
 
 	coladd = pos->coladd;
 	endadd = 0;
-# ifdef FEAT_MBYTE
 	/* Cannot put the cursor on part of a wide character. */
 	ptr = ml_get_buf(wp->w_buffer, pos->lnum, FALSE);
 	if (pos->col < (colnr_T)STRLEN(ptr))
@@ -1487,7 +1415,6 @@ getvvcol(
 		    coladd = 0;
 	    }
 	}
-# endif
 	col += coladd;
 	if (start != NULL)
 	    *start = col;
@@ -1684,7 +1611,6 @@ vim_isbdigit(int c)
     return (c == '0' || c == '1');
 }
 
-#if defined(FEAT_MBYTE) || defined(PROTO)
 /*
  * Vim's own character class functions.  These exist because many library
  * islower()/toupper() etc. do not work properly: they crash when used with
@@ -1797,7 +1723,6 @@ vim_tolower(int c)
 	return TOLOWER_ASC(c);
     return TOLOWER_LOC(c);
 }
-#endif
 
 /*
  * skiptowhite: skip over text until ' ' or '\t' or NUL.
@@ -2077,9 +2002,7 @@ rem_backslash(char_u *str)
 {
 #ifdef BACKSLASH_IN_FILENAME
     return (str[0] == '\\'
-# ifdef FEAT_MBYTE
 	    && str[1] < 0x80
-# endif
 	    && (str[1] == ' '
 		|| (str[1] != NUL
 		    && str[1] != '*'