diff --git a/libutil/unescape.c b/libutil/unescape.c
index bf29230..627c2a2 100644
--- a/libutil/unescape.c
+++ b/libutil/unescape.c
@@ -51,8 +51,8 @@ unescape(char *s)
 		case '\0':
 			eprintf("%s: null escape sequence\n", argv0);
 		default:
-			/* "\O[OO]" octal escape */
-			for (m = i + 1; m < i + 1 + 3 && m < len; m++)
+			/* "\O[OOO]" octal escape */
+			for (m = i + 1; m < i + 1 + 4 && m < len; m++)
 				if (s[m] < '0' || s[m] > '7')
 					break;
 			if (m == i + 1)