diff --git a/main/say.c b/main/say.c
index 5e3ae96d9b..7f79273084 100644
--- a/main/say.c
+++ b/main/say.c
@@ -4212,7 +4212,7 @@ int ast_say_date_with_format_th(struct ast_channel *chan, time_t t, const char *
 			case '\'':
 				/* Literal name of a sound file */
 				sndoffset=0;
-				for (sndoffset=0 ; (format[++offset] != '\'') && (sndoffset < 256) ; sndoffset++)
+				for (sndoffset=0 ; (format[++offset] != '\'') && (sndoffset < sizeof(sndfile) - 1) ; sndoffset++)
 					sndfile[sndoffset] = format[offset];
 				sndfile[sndoffset] = '\0';
 				res = wait_file(chan, ints, sndfile, lang);