diff --git a/tinycss2/ast.py b/tinycss2/ast.py
index 610bdcb..0919d18 100644
--- a/tinycss2/ast.py
+++ b/tinycss2/ast.py
@@ -384,7 +384,7 @@ def _serialize_to(self, write):
 
 
 class UnicodeRangeToken(Node):
-    """A `unicode-range token <https://www.w3.org/TR/css-syntax-3/#urange>`_.
+    """A :diagram:`unicode-range-token`.
 
     .. autoattribute:: type