diff --git a/specs/jsonschema-core.md b/specs/jsonschema-core.md
index 510300b8..c3e260cf 100644
--- a/specs/jsonschema-core.md
+++ b/specs/jsonschema-core.md
@@ -957,8 +957,8 @@ resources, unless such a resource itself declares a different dialect by
 including the `$schema` keyword with a different value.
 
 The value of this keyword MUST be an
-[IRI](https://www.rfc-editor.org/info/rfc3987) (containing a scheme) and this
-IRI MUST be normalized.
+[IRI](https://www.rfc-editor.org/info/rfc3987) (containing a scheme). This
+IRI MUST be normalized and MUST NOT contain a fragment.
 
 If this IRI identifies a retrievable resource, that resource SHOULD be of media
 type `application/schema+json`.
</div><div class="naked_ctrl">
<form action="/index.cgi/contrast" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://patch-diff.githubusercontent.com/raw/json-schema-org/json-schema-spec/pull/1633.diff">(-&gt;オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://patch-diff.githubusercontent.com/raw/json-schema-org/json-schema-spec/pull/1633.diff" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast" selected="selected">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>