diff --git a/spec.emu b/spec.emu
index c56fe7a..ef79948 100644
--- a/spec.emu
+++ b/spec.emu
@@ -25,8 +25,8 @@ contributors: Jordan Harband
It performs the following steps when called:
- 1. Let _str_ be ? ToString(_S_).
- 1. Let _cpList_ be StringToCodePoints(_str_).
+ 1. If _S_ is not a String, throw a TypeError exception.
+ 1. Let _cpList_ be StringToCodePoints(_S_).
1. Let _escapedList_ be a new empty List.
1. For each code point _c_ in _cpList_, do
1. If _escapedList_ is empty and _c_ is matched by |DecimalDigit|, then