diff --git a/tests/ui/needless_borrows_for_generic_args.fixed b/tests/ui/needless_borrows_for_generic_args.fixed
index 593649b60bc..c1dc8b5e8d0 100644
--- a/tests/ui/needless_borrows_for_generic_args.fixed
+++ b/tests/ui/needless_borrows_for_generic_args.fixed
@@ -336,7 +336,7 @@ fn main() {
     {
         fn takes_writer<T: std::io::Write>(_: T) {}
 
-        fn f(mut buffer: &mut Vec<u8>) {
+        fn issue_12856(mut buffer: &mut Vec<u8>) {
             takes_writer(&mut buffer); // Don't lint, would make buffer unavailable later
             buffer.extend(b"\n");
         }
diff --git a/tests/ui/needless_borrows_for_generic_args.rs b/tests/ui/needless_borrows_for_generic_args.rs
index 0c9b98d739d..c7f66824d58 100644
--- a/tests/ui/needless_borrows_for_generic_args.rs
+++ b/tests/ui/needless_borrows_for_generic_args.rs
@@ -336,7 +336,7 @@ fn f(_: impl AsRef<str>) {}
     {
         fn takes_writer<T: std::io::Write>(_: T) {}
 
-        fn f(mut buffer: &mut Vec<u8>) {
+        fn issue_12856(mut buffer: &mut Vec<u8>) {
             takes_writer(&mut buffer); // Don't lint, would make buffer unavailable later
             buffer.extend(b"\n");
         }