diff --git a/library/test/src/lib.rs b/library/test/src/lib.rs
index 2516f3452b186..608e587cf34f3 100644
--- a/library/test/src/lib.rs
+++ b/library/test/src/lib.rs
@@ -13,20 +13,12 @@
 // running tests while providing a base that other test frameworks may
 // build off of.
 
-// N.B., this is also specified in this crate's Cargo.toml, but librustc_ast contains logic specific to
-// this crate, which relies on this attribute (rather than the value of `--crate-name` passed by
-// cargo) to detect this crate.
-
-#![crate_name = "test"]
 #![unstable(feature = "test", issue = "50297")]
 #![doc(test(attr(deny(warnings))))]
-#![feature(libc)]
-#![feature(rustc_private)]
 #![feature(nll)]
 #![feature(available_parallelism)]
 #![feature(bench_black_box)]
 #![feature(internal_output_capture)]
-#![feature(panic_unwind)]
 #![feature(staged_api)]
 #![feature(termination_trait_lib)]
 #![feature(test)]
@@ -444,8 +436,8 @@ pub fn convert_benchmarks_to_tests(tests: Vec<TestDescAndFn>) -> Vec<TestDescAnd
         .into_iter()
         .map(|x| {
             let testfn = match x.testfn {
-                DynBenchFn(bench) => DynTestFn(Box::new(move || {
-                    bench::run_once(|b| __rust_begin_short_backtrace(|| bench.run(b)))
+                DynBenchFn(benchfn) => DynTestFn(Box::new(move || {
+                    bench::run_once(|b| __rust_begin_short_backtrace(|| benchfn(b)))
                 })),
                 StaticBenchFn(benchfn) => DynTestFn(Box::new(move || {
                     bench::run_once(|b| __rust_begin_short_backtrace(|| benchfn(b)))
@@ -544,11 +536,9 @@ pub fn run_test(
         TestRunOpts { strategy, nocapture: opts.nocapture, concurrency, time: opts.time_options };
 
     match testfn {
-        DynBenchFn(bencher) => {
+        DynBenchFn(benchfn) => {
             // Benchmarks aren't expected to panic, so we run them all in-process.
-            crate::bench::benchmark(id, desc, monitor_ch, opts.nocapture, |harness| {
-                bencher.run(harness)
-            });
+            crate::bench::benchmark(id, desc, monitor_ch, opts.nocapture, benchfn);
             None
         }
         StaticBenchFn(benchfn) => {
diff --git a/library/test/src/stats.rs b/library/test/src/stats.rs
index 45fae9c76b44d..40b05704b40cb 100644
--- a/library/test/src/stats.rs
+++ b/library/test/src/stats.rs
@@ -1,5 +1,4 @@
 #![allow(missing_docs)]
-#![allow(deprecated)] // Float
 
 use std::mem;
 
diff --git a/library/test/src/types.rs b/library/test/src/types.rs
index 3512a57e8e4ae..37bb38fb0df4e 100644
--- a/library/test/src/types.rs
+++ b/library/test/src/types.rs
@@ -74,11 +74,6 @@ impl fmt::Display for TestName {
     }
 }
 
-/// Represents a benchmark function.
-pub trait TDynBenchFn: Send {
-    fn run(&self, harness: &mut Bencher);
-}
-
 // A function that runs a test. If the function returns successfully,
 // the test succeeds; if the function panics then the test fails. We
 // may need to come up with a more clever definition of test in order
@@ -87,7 +82,7 @@ pub enum TestFn {
     StaticTestFn(fn()),
     StaticBenchFn(fn(&mut Bencher)),
     DynTestFn(Box<dyn FnOnce() + Send>),
-    DynBenchFn(Box<dyn TDynBenchFn + 'static>),
+    DynBenchFn(Box<dyn Fn(&mut Bencher) + Send>),
 }
 
 impl TestFn {