Release 0.13.0
diff --git a/examples/trace-var/README.md b/examples/trace-var/README.md
index 52e50ba..f8dde65 100644
--- a/examples/trace-var/README.md
+++ b/examples/trace-var/README.md
@@ -42,7 +42,7 @@
 The procedural macro uses a syntax tree [`Fold`] to rewrite every `let`
 statement and assignment expression in the following way:
 
-[`Fold`]: https://docs.rs/syn/0.12/syn/fold/trait.Fold.html
+[`Fold`]: https://docs.rs/syn/0.13/syn/fold/trait.Fold.html
 
 ```rust
 // Before