diff -r 99b2236c037c src/buffer.c
--- a/src/buffer.c	Mon Jun 03 12:17:05 2013 +0200
+++ b/src/buffer.c	Mon Jun 03 16:23:39 2013 +0200
@@ -3567,11 +3567,6 @@
 
     if (fillchar == 0)
 	fillchar = ' ';
-#ifdef FEAT_MBYTE
-    /* Can't handle a multi-byte fill character yet. */
-    else if (mb_char2len(fillchar) > 1)
-	fillchar = '-';
-#endif
 
     /* Get line & check if empty (cursorpos will show "0-1").  Note that
      * p will become invalid when getting another buffer line. */
@@ -4278,12 +4273,17 @@
 		break;
 	if (l < itemcnt)
 	{
-	    p = item[l].start + maxwidth - width;
+	    int middlelength = (maxwidth - width) * MB_CHAR2LEN(fillchar);
+	    p = item[l].start + middlelength;
 	    STRMOVE(p, item[l].start);
-	    for (s = item[l].start; s < p; s++)
-		*s = fillchar;
+	    for (s = item[l].start; s < p;)
+#ifdef FEAT_MBYTE
+		s += (*mb_char2bytes)(fillchar, s);
+#else
+		*s++ = fillchar;
+#endif
 	    for (l++; l < itemcnt; l++)
-		item[l].start += maxwidth - width;
+		item[l].start += middlelength;
 	    width = maxwidth;
 	}
     }
diff -r 99b2236c037c src/macros.h
--- a/src/macros.h	Mon Jun 03 12:17:05 2013 +0200
+++ b/src/macros.h	Mon Jun 03 16:23:39 2013 +0200
@@ -261,6 +261,8 @@
 #ifdef FEAT_MBYTE
 /* Get the length of the character p points to */
 # define MB_PTR2LEN(p)		(has_mbyte ? (*mb_ptr2len)(p) : 1)
+/* Get the byte length of the character p */
+# define MB_CHAR2LEN(p)		(has_mbyte ? (*mb_char2len)(p) : 1)
 /* Advance multi-byte pointer, skip over composing chars. */
 # define mb_ptr_adv(p)	    p += has_mbyte ? (*mb_ptr2len)(p) : 1
 /* Advance multi-byte pointer, do not skip over composing chars. */
@@ -275,6 +277,7 @@
 # define PTR2CHAR(p)	    (has_mbyte ? mb_ptr2char(p) : (int)*(p))
 #else
 # define MB_PTR2LEN(p)		1
+# define MB_CHAR2LEN(p)		1
 # define mb_ptr_adv(p)		++p
 # define mb_cptr_adv(p)		++p
 # define mb_ptr_back(s, p)	--p