diff --git a/README.md b/README.md
index cfe8497..8426b45 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,7 @@ macro_rules! js_concat {
 
 This emits the following error [^error-message]:
 ```none
-error: Potentially invalid expansion. Expected `break`, `if`, `return`, a `[`, a `{`, a literal, an identifier.
+error: Potentially invalid expansion. Expected `::`, `break`, `if`, `return`, a `[`, a `{`, a literal, an identifier.
  --> tests/ui/fail/js_concat.rs:5:16
   |
 5 |         $left ++ $right