diff --git a/library/core/benches/iter.rs b/library/core/benches/iter.rs
index 24257ba98785d..0abe20e4ca3b2 100644
--- a/library/core/benches/iter.rs
+++ b/library/core/benches/iter.rs
@@ -367,3 +367,27 @@ fn bench_partial_cmp(b: &mut Bencher) {
 fn bench_lt(b: &mut Bencher) {
     b.iter(|| (0..100000).map(black_box).lt((0..100000).map(black_box)))
 }
+
+#[bench]
+fn bench_trusted_random_access_adapters(b: &mut Bencher) {
+    let vec1: Vec<_> = (0usize..100000).collect();
+    let vec2 = black_box(vec1.clone());
+    b.iter(|| {
+        let mut iter = vec1
+            .iter()
+            .copied()
+            .enumerate()
+            .map(|(idx, e)| idx.wrapping_add(e))
+            .zip(vec2.iter().copied())
+            .map(|(a, b)| a.wrapping_add(b))
+            .fuse();
+        let mut acc: usize = 0;
+        let size = iter.size();
+        for i in 0..size {
+            // SAFETY: TRA requirements are satisfied by 0..size iteration and then dropping the
+            // iterator.
+            acc = acc.wrapping_add(unsafe { iter.__iterator_get_unchecked(i) });
+        }
+        acc
+    })
+}
diff --git a/library/core/benches/lib.rs b/library/core/benches/lib.rs
index d5e1ec083f95d..f1f1ae6e4635d 100644
--- a/library/core/benches/lib.rs
+++ b/library/core/benches/lib.rs
@@ -3,6 +3,7 @@
 #![feature(flt2dec)]
 #![feature(int_log)]
 #![feature(test)]
+#![feature(trusted_random_access)]
 
 extern crate test;
 
diff --git a/library/core/src/iter/adapters/enumerate.rs b/library/core/src/iter/adapters/enumerate.rs
index 84e4618844a61..10b4db84b3904 100644
--- a/library/core/src/iter/adapters/enumerate.rs
+++ b/library/core/src/iter/adapters/enumerate.rs
@@ -129,6 +129,7 @@ where
 
     #[rustc_inherit_overflow_checks]
     #[doc(hidden)]
+    #[inline]
     unsafe fn __iterator_get_unchecked(&mut self, idx: usize) -> <Self as Iterator>::Item
     where
         Self: TrustedRandomAccessNoCoerce,
diff --git a/library/core/src/iter/adapters/map.rs b/library/core/src/iter/adapters/map.rs
index 4b03449972c9a..6cbb35dc7c629 100644
--- a/library/core/src/iter/adapters/map.rs
+++ b/library/core/src/iter/adapters/map.rs
@@ -125,6 +125,7 @@ where
     }
 
     #[doc(hidden)]
+    #[inline]
     unsafe fn __iterator_get_unchecked(&mut self, idx: usize) -> B
     where
         Self: TrustedRandomAccessNoCoerce,
diff --git a/library/core/src/iter/adapters/zip.rs b/library/core/src/iter/adapters/zip.rs
index f50e71da20f16..de44bd66501e2 100644
--- a/library/core/src/iter/adapters/zip.rs
+++ b/library/core/src/iter/adapters/zip.rs
@@ -554,6 +554,7 @@ pub unsafe trait TrustedRandomAccessNoCoerce: Sized {
 ///
 /// Same requirements calling `get_unchecked` directly.
 #[doc(hidden)]
+#[inline]
 pub(in crate::iter::adapters) unsafe fn try_get_unchecked<I>(it: &mut I, idx: usize) -> I::Item
 where
     I: Iterator,
@@ -576,6 +577,7 @@ unsafe impl<I: Iterator> SpecTrustedRandomAccess for I {
 }
 
 unsafe impl<I: Iterator + TrustedRandomAccessNoCoerce> SpecTrustedRandomAccess for I {
+    #[inline]
     unsafe fn try_get_unchecked(&mut self, index: usize) -> Self::Item {
         // SAFETY: the caller must uphold the contract for
         // `Iterator::__iterator_get_unchecked`.
diff --git a/library/core/src/slice/iter/macros.rs b/library/core/src/slice/iter/macros.rs
index b74ab28fc092a..78bf3381b4d26 100644
--- a/library/core/src/slice/iter/macros.rs
+++ b/library/core/src/slice/iter/macros.rs
@@ -326,6 +326,7 @@ macro_rules! iterator {
             }
 
             #[doc(hidden)]
+            #[inline]
             unsafe fn __iterator_get_unchecked(&mut self, idx: usize) -> Self::Item {
                 // SAFETY: the caller must guarantee that `i` is in bounds of
                 // the underlying slice, so `i` cannot overflow an `isize`, and