diff --git a/src/liballoc/collections/mod.rs b/src/liballoc/collections/mod.rs
index 5a33ddc14f0..48c3ed8a57d 100644
--- a/src/liballoc/collections/mod.rs
+++ b/src/liballoc/collections/mod.rs
@@ -46,7 +46,7 @@ use crate::alloc::{AllocErr, LayoutErr};
 /// Augments `AllocErr` with a CapacityOverflow variant.
 #[derive(Clone, PartialEq, Eq, Debug)]
 #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-pub enum CollectionAllocErr {
+pub enum TryReserveError {
     /// Error due to the computed capacity exceeding the collection's maximum
     /// (usually `isize::MAX` bytes).
     CapacityOverflow,
@@ -55,18 +55,18 @@ pub enum CollectionAllocErr {
 }
 
 #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-impl From<AllocErr> for CollectionAllocErr {
+impl From<AllocErr> for TryReserveError {
     #[inline]
     fn from(AllocErr: AllocErr) -> Self {
-        CollectionAllocErr::AllocErr
+        TryReserveError::AllocErr
     }
 }
 
 #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-impl From<LayoutErr> for CollectionAllocErr {
+impl From<LayoutErr> for TryReserveError {
     #[inline]
     fn from(_: LayoutErr) -> Self {
-        CollectionAllocErr::CapacityOverflow
+        TryReserveError::CapacityOverflow
     }
 }
 
diff --git a/src/liballoc/collections/vec_deque.rs b/src/liballoc/collections/vec_deque.rs
index 9240346ace9..2fc87413367 100644
--- a/src/liballoc/collections/vec_deque.rs
+++ b/src/liballoc/collections/vec_deque.rs
@@ -18,7 +18,7 @@ use core::ptr::{self, NonNull};
 use core::slice;
 use core::hash::{Hash, Hasher};
 
-use crate::collections::CollectionAllocErr;
+use crate::collections::TryReserveError;
 use crate::raw_vec::RawVec;
 use crate::vec::Vec;
 
@@ -576,10 +576,10 @@ impl<T> VecDeque<T> {
     ///
     /// ```
     /// #![feature(try_reserve)]
-    /// use std::collections::CollectionAllocErr;
+    /// use std::collections::TryReserveError;
     /// use std::collections::VecDeque;
     ///
-    /// fn process_data(data: &[u32]) -> Result<VecDeque<u32>, CollectionAllocErr> {
+    /// fn process_data(data: &[u32]) -> Result<VecDeque<u32>, TryReserveError> {
     ///     let mut output = VecDeque::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
@@ -595,7 +595,7 @@ impl<T> VecDeque<T> {
     /// # process_data(&[1, 2, 3]).expect("why is the test harness OOMing on 12 bytes?");
     /// ```
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), CollectionAllocErr>  {
+    pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError>  {
         self.try_reserve(additional)
     }
 
@@ -614,10 +614,10 @@ impl<T> VecDeque<T> {
     ///
     /// ```
     /// #![feature(try_reserve)]
-    /// use std::collections::CollectionAllocErr;
+    /// use std::collections::TryReserveError;
     /// use std::collections::VecDeque;
     ///
-    /// fn process_data(data: &[u32]) -> Result<VecDeque<u32>, CollectionAllocErr> {
+    /// fn process_data(data: &[u32]) -> Result<VecDeque<u32>, TryReserveError> {
     ///     let mut output = VecDeque::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
@@ -633,12 +633,12 @@ impl<T> VecDeque<T> {
     /// # process_data(&[1, 2, 3]).expect("why is the test harness OOMing on 12 bytes?");
     /// ```
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve(&mut self, additional: usize) -> Result<(), CollectionAllocErr> {
+    pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
         let old_cap = self.cap();
         let used_cap = self.len() + 1;
         let new_cap = used_cap.checked_add(additional)
             .and_then(|needed_cap| needed_cap.checked_next_power_of_two())
-            .ok_or(CollectionAllocErr::CapacityOverflow)?;
+            .ok_or(TryReserveError::CapacityOverflow)?;
 
         if new_cap > old_cap {
             self.buf.try_reserve_exact(used_cap, new_cap - used_cap)?;
diff --git a/src/liballoc/raw_vec.rs b/src/liballoc/raw_vec.rs
index 0abab45e920..fed5a16599d 100644
--- a/src/liballoc/raw_vec.rs
+++ b/src/liballoc/raw_vec.rs
@@ -8,7 +8,7 @@ use core::ptr::{self, NonNull, Unique};
 use core::slice;
 
 use crate::alloc::{Alloc, Layout, Global, handle_alloc_error};
-use crate::collections::CollectionAllocErr::{self, *};
+use crate::collections::TryReserveError::{self, *};
 use crate::boxed::Box;
 
 #[cfg(test)]
@@ -385,7 +385,7 @@ impl<T, A: Alloc> RawVec<T, A> {
 
     /// The same as `reserve_exact`, but returns on errors instead of panicking or aborting.
     pub fn try_reserve_exact(&mut self, used_capacity: usize, needed_extra_capacity: usize)
-           -> Result<(), CollectionAllocErr> {
+           -> Result<(), TryReserveError> {
 
         self.reserve_internal(used_capacity, needed_extra_capacity, Fallible, Exact)
     }
@@ -422,7 +422,7 @@ impl<T, A: Alloc> RawVec<T, A> {
     /// needed_extra_capacity` elements. This logic is used in amortized reserve methods.
     /// Returns `(new_capacity, new_alloc_size)`.
     fn amortized_new_size(&self, used_capacity: usize, needed_extra_capacity: usize)
-        -> Result<usize, CollectionAllocErr> {
+        -> Result<usize, TryReserveError> {
 
         // Nothing we can really do about these checks :(
         let required_cap = used_capacity.checked_add(needed_extra_capacity)
@@ -435,7 +435,7 @@ impl<T, A: Alloc> RawVec<T, A> {
 
     /// The same as `reserve`, but returns on errors instead of panicking or aborting.
     pub fn try_reserve(&mut self, used_capacity: usize, needed_extra_capacity: usize)
-        -> Result<(), CollectionAllocErr> {
+        -> Result<(), TryReserveError> {
         self.reserve_internal(used_capacity, needed_extra_capacity, Fallible, Amortized)
     }
 
@@ -640,7 +640,7 @@ impl<T, A: Alloc> RawVec<T, A> {
         needed_extra_capacity: usize,
         fallibility: Fallibility,
         strategy: ReserveStrategy,
-    ) -> Result<(), CollectionAllocErr> {
+    ) -> Result<(), TryReserveError> {
         unsafe {
             use crate::alloc::AllocErr;
 
@@ -737,7 +737,7 @@ unsafe impl<#[may_dangle] T, A: Alloc> Drop for RawVec<T, A> {
 // all 4GB in user-space. e.g., PAE or x32
 
 #[inline]
-fn alloc_guard(alloc_size: usize) -> Result<(), CollectionAllocErr> {
+fn alloc_guard(alloc_size: usize) -> Result<(), TryReserveError> {
     if mem::size_of::<usize>() < 8 && alloc_size > core::isize::MAX as usize {
         Err(CapacityOverflow)
     } else {
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index eca726cd410..b65f191836e 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -56,7 +56,7 @@ use core::ptr;
 use core::str::{pattern::Pattern, lossy};
 
 use crate::borrow::{Cow, ToOwned};
-use crate::collections::CollectionAllocErr;
+use crate::collections::TryReserveError;
 use crate::boxed::Box;
 use crate::str::{self, from_boxed_utf8_unchecked, FromStr, Utf8Error, Chars};
 use crate::vec::Vec;
@@ -937,9 +937,9 @@ impl String {
     ///
     /// ```
     /// #![feature(try_reserve)]
-    /// use std::collections::CollectionAllocErr;
+    /// use std::collections::TryReserveError;
     ///
-    /// fn process_data(data: &str) -> Result<String, CollectionAllocErr> {
+    /// fn process_data(data: &str) -> Result<String, TryReserveError> {
     ///     let mut output = String::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
@@ -953,7 +953,7 @@ impl String {
     /// # process_data("rust").expect("why is the test harness OOMing on 4 bytes?");
     /// ```
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve(&mut self, additional: usize) -> Result<(), CollectionAllocErr> {
+    pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
         self.vec.try_reserve(additional)
     }
 
@@ -975,9 +975,9 @@ impl String {
     ///
     /// ```
     /// #![feature(try_reserve)]
-    /// use std::collections::CollectionAllocErr;
+    /// use std::collections::TryReserveError;
     ///
-    /// fn process_data(data: &str) -> Result<String, CollectionAllocErr> {
+    /// fn process_data(data: &str) -> Result<String, TryReserveError> {
     ///     let mut output = String::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
@@ -991,7 +991,7 @@ impl String {
     /// # process_data("rust").expect("why is the test harness OOMing on 4 bytes?");
     /// ```
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), CollectionAllocErr>  {
+    pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError>  {
         self.vec.try_reserve_exact(additional)
     }
 
diff --git a/src/liballoc/tests/string.rs b/src/liballoc/tests/string.rs
index 765210e5aa6..4d2ea42fcae 100644
--- a/src/liballoc/tests/string.rs
+++ b/src/liballoc/tests/string.rs
@@ -1,5 +1,5 @@
 use std::borrow::Cow;
-use std::collections::CollectionAllocErr::*;
+use std::collections::TryReserveError::*;
 use std::mem::size_of;
 use std::{usize, isize};
 
diff --git a/src/liballoc/tests/vec.rs b/src/liballoc/tests/vec.rs
index 6e8ffe18522..c67ec32543b 100644
--- a/src/liballoc/tests/vec.rs
+++ b/src/liballoc/tests/vec.rs
@@ -2,7 +2,7 @@ use std::borrow::Cow;
 use std::mem::size_of;
 use std::{usize, isize};
 use std::vec::{Drain, IntoIter};
-use std::collections::CollectionAllocErr::*;
+use std::collections::TryReserveError::*;
 
 struct DropCounter<'a> {
     count: &'a mut u32,
diff --git a/src/liballoc/tests/vec_deque.rs b/src/liballoc/tests/vec_deque.rs
index 1bbcca97b3c..c7e743c2e94 100644
--- a/src/liballoc/tests/vec_deque.rs
+++ b/src/liballoc/tests/vec_deque.rs
@@ -1,6 +1,6 @@
 use std::fmt::Debug;
 use std::collections::{VecDeque, vec_deque::Drain};
-use std::collections::CollectionAllocErr::*;
+use std::collections::TryReserveError::*;
 use std::mem::size_of;
 use std::{usize, isize};
 
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index dac04e4e624..d2798955c46 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -70,7 +70,7 @@ use core::ptr::{self, NonNull};
 use core::slice::{self, SliceIndex};
 
 use crate::borrow::{ToOwned, Cow};
-use crate::collections::CollectionAllocErr;
+use crate::collections::TryReserveError;
 use crate::boxed::Box;
 use crate::raw_vec::RawVec;
 
@@ -498,9 +498,9 @@ impl<T> Vec<T> {
     ///
     /// ```
     /// #![feature(try_reserve)]
-    /// use std::collections::CollectionAllocErr;
+    /// use std::collections::TryReserveError;
     ///
-    /// fn process_data(data: &[u32]) -> Result<Vec<u32>, CollectionAllocErr> {
+    /// fn process_data(data: &[u32]) -> Result<Vec<u32>, TryReserveError> {
     ///     let mut output = Vec::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
@@ -516,7 +516,7 @@ impl<T> Vec<T> {
     /// # process_data(&[1, 2, 3]).expect("why is the test harness OOMing on 12 bytes?");
     /// ```
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve(&mut self, additional: usize) -> Result<(), CollectionAllocErr> {
+    pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
         self.buf.try_reserve(self.len, additional)
     }
 
@@ -538,9 +538,9 @@ impl<T> Vec<T> {
     ///
     /// ```
     /// #![feature(try_reserve)]
-    /// use std::collections::CollectionAllocErr;
+    /// use std::collections::TryReserveError;
     ///
-    /// fn process_data(data: &[u32]) -> Result<Vec<u32>, CollectionAllocErr> {
+    /// fn process_data(data: &[u32]) -> Result<Vec<u32>, TryReserveError> {
     ///     let mut output = Vec::new();
     ///
     ///     // Pre-reserve the memory, exiting if we can't
@@ -556,7 +556,7 @@ impl<T> Vec<T> {
     /// # process_data(&[1, 2, 3]).expect("why is the test harness OOMing on 12 bytes?");
     /// ```
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), CollectionAllocErr>  {
+    pub fn try_reserve_exact(&mut self, additional: usize) -> Result<(), TryReserveError>  {
         self.buf.try_reserve_exact(self.len, additional)
     }
 
diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 1e28ee8da26..8581cf13b08 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -6,7 +6,7 @@ use hashbrown::hash_map as base;
 
 use crate::borrow::Borrow;
 use crate::cell::Cell;
-use crate::collections::CollectionAllocErr;
+use crate::collections::TryReserveError;
 use crate::fmt::{self, Debug};
 #[allow(deprecated)]
 use crate::hash::{BuildHasher, Hash, Hasher, SipHasher13};
@@ -588,7 +588,7 @@ where
     /// ```
     #[inline]
     #[unstable(feature = "try_reserve", reason = "new API", issue = "48043")]
-    pub fn try_reserve(&mut self, additional: usize) -> Result<(), CollectionAllocErr> {
+    pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
         self.base
             .try_reserve(additional)
             .map_err(map_collection_alloc_err)
@@ -2542,10 +2542,10 @@ fn map_entry<'a, K: 'a, V: 'a>(raw: base::RustcEntry<'a, K, V>) -> Entry<'a, K,
 }
 
 #[inline]
-fn map_collection_alloc_err(err: hashbrown::CollectionAllocErr) -> CollectionAllocErr {
+fn map_collection_alloc_err(err: hashbrown::CollectionAllocErr) -> TryReserveError {
     match err {
-        hashbrown::CollectionAllocErr::CapacityOverflow => CollectionAllocErr::CapacityOverflow,
-        hashbrown::CollectionAllocErr::AllocErr => CollectionAllocErr::AllocErr,
+        hashbrown::CollectionAllocErr::CapacityOverflow => TryReserveError::CapacityOverflow,
+        hashbrown::CollectionAllocErr::AllocErr => TryReserveError::AllocErr,
     }
 }
 
@@ -2605,7 +2605,7 @@ mod test_map {
     use super::RandomState;
     use crate::cell::RefCell;
     use rand::{thread_rng, Rng};
-    use realstd::collections::CollectionAllocErr::*;
+    use realstd::collections::TryReserveError::*;
     use realstd::usize;
 
     // https://github.com/rust-lang/rust/issues/62301
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index d243412405a..26db651ef89 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -1,5 +1,5 @@
 use crate::borrow::Borrow;
-use crate::collections::CollectionAllocErr;
+use crate::collections::TryReserveError;
 use crate::fmt;
 use crate::hash::{Hash, BuildHasher};
 use crate::iter::{Chain, FromIterator, FusedIterator};
@@ -383,7 +383,7 @@ impl<T, S> HashSet<T, S>
     /// ```
     #[inline]
     #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-    pub fn try_reserve(&mut self, additional: usize) -> Result<(), CollectionAllocErr> {
+    pub fn try_reserve(&mut self, additional: usize) -> Result<(), TryReserveError> {
         self.map.try_reserve(additional)
     }
 
diff --git a/src/libstd/collections/mod.rs b/src/libstd/collections/mod.rs
index 15c2532f8b4..f5957466be8 100644
--- a/src/libstd/collections/mod.rs
+++ b/src/libstd/collections/mod.rs
@@ -427,7 +427,7 @@ pub use self::hash_map::HashMap;
 pub use self::hash_set::HashSet;
 
 #[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-pub use alloc_crate::collections::CollectionAllocErr;
+pub use alloc_crate::collections::TryReserveError;
 
 mod hash;