diff --git a/src/charset.c b/src/charset.c
index f41248b..f3d12cb 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -1095,7 +1095,7 @@
 		char_u *p = ((char_u **)wp->w_buffer->b_textprop_text.ga_data)[
 							       -tp->tp_id - 1];
 		// TODO: count screen cells
-		cts->cts_cur_text_width = STRLEN(p);
+		cts->cts_cur_text_width = (int)STRLEN(p);
 		size += cts->cts_cur_text_width;
 		break;
 	    }