diff --git a/st.c b/st.c
index f2b3095..839136d 100644
--- a/st.c
+++ b/st.c
@@ -3291,7 +3291,7 @@ xloadfont(Font *f, FcPattern *pattern)
 
 	XftTextExtentsUtf8(xw.dpy, f->match,
 		(const FcChar8 *) ascii_printable,
-		LEN(ascii_printable), &extents);
+		strlen(ascii_printable), &extents);
 
 	f->set = NULL;
 	f->pattern = FcPatternDuplicate(pattern);
@@ -3302,7 +3302,7 @@ xloadfont(Font *f, FcPattern *pattern)
 	f->rbearing = f->match->max_advance_width;
 
 	f->height = f->ascent + f->descent;
-	f->width = DIVCEIL(extents.xOff, LEN(ascii_printable));
+	f->width = DIVCEIL(extents.xOff, strlen(ascii_printable));
 
 	return 0;
 }