diff --git a/ext/standard/array.c b/ext/standard/array.c
index 30a19610e3b..829b6dcf019 100644
--- a/ext/standard/array.c
+++ b/ext/standard/array.c
@@ -188,7 +188,7 @@ static zend_always_inline int php_array_key_compare_string_case_unstable_i(Bucke
 		l2 = s->key->len;
 	} else {
 		s2 = zend_print_long_to_buf(buf2 + sizeof(buf2) - 1, s->h);
-		l2 = buf2 + sizeof(buf2) - 1 - s1;
+		l2 = buf2 + sizeof(buf2) - 1 - s2;
 	}
 	return zend_binary_strcasecmp_l(s1, l1, s2, l2);
 }