diff --git a/src/test/ui/feature-gates/feature-gate-const_generics.stderr b/src/test/ui/feature-gates/feature-gate-const_generics.stderr
index b2b7e4576bf..ed19109b38b 100644
--- a/src/test/ui/feature-gates/feature-gate-const_generics.stderr
+++ b/src/test/ui/feature-gates/feature-gate-const_generics.stderr
@@ -5,7 +5,7 @@ LL | fn foo<const X: ()>() {}
    |                 ^^
    |
    = note: the only supported types are integers, `bool` and `char`
-   = help: more complex types are supported with `#[feature(const_generics)]`
+   = help: more complex types are supported with `#![feature(const_generics)]`
 
 error: aborting due to previous error