diff --git a/src/screen.c b/src/screen.c
index 5b9a073..74898f8 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -6168,8 +6168,8 @@
 		int	clen = 0, i;
 
 		/* Count total number of display cells. */
-		for (i = 0; p[i] != NUL; i += (*mb_ptr2len)(p + i))
-		    clen += (*mb_ptr2cells)(p + i);
+		clen = mb_string2cells(p, -1);
+
 		/* Find first character that will fit.
 		 * Going from start to end is much faster for DBCS. */
 		for (i = 0; p[i] != NUL && clen >= this_ru_col - 1;