diff --git a/src/libstd/collections/hash/bench.rs b/src/liballoc/collections/hash/bench.rs
similarity index 100%
rename from src/libstd/collections/hash/bench.rs
rename to src/liballoc/collections/hash/bench.rs
diff --git a/src/libstd/collections/hash/map.rs b/src/liballoc/collections/hash/map.rs
similarity index 98%
rename from src/libstd/collections/hash/map.rs
rename to src/liballoc/collections/hash/map.rs
index 91912e5f2412e..0f0379990f808 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/liballoc/collections/hash/map.rs
@@ -12,16 +12,14 @@ use self::Entry::*;
 use self::VacantEntryState::*;
 
 use collections::CollectionAllocErr;
-use cell::Cell;
-use borrow::Borrow;
-use cmp::max;
-use fmt::{self, Debug};
+use core::borrow::Borrow;
+use core::cmp::max;
+use core::fmt::{self, Debug};
 #[allow(deprecated)]
-use hash::{Hash, Hasher, BuildHasher, SipHasher13};
-use iter::{FromIterator, FusedIterator};
-use mem::{self, replace};
-use ops::{Deref, Index};
-use sys;
+use core::hash::{Hash, Hasher, BuildHasher, SipHasher13};
+use core::iter::{FromIterator, FusedIterator};
+use core::mem::{self, replace};
+use core::ops::{Deref, Index};
 
 use super::table::{self, Bucket, EmptyBucket, Fallibility, FullBucket, FullBucketMut, RawTable,
                    SafeHash};
@@ -2561,7 +2559,7 @@ impl<'a, K, V, S> Extend<(&'a K, &'a V)> for HashMap<K, V, S>
 /// instances are unlikely to produce the same result for the same values.
 ///
 /// [`HashMap`]: struct.HashMap.html
-/// [`Hasher`]: ../../hash/trait.Hasher.html
+/// [`Hasher`]: ../../../std/hash/trait.Hasher.html
 ///
 /// # Examples
 ///
@@ -2592,29 +2590,22 @@ impl RandomState {
     /// ```
     #[inline]
     #[allow(deprecated)]
-    // rand
     #[stable(feature = "hashmap_build_hasher", since = "1.7.0")]
     pub fn new() -> RandomState {
-        // Historically this function did not cache keys from the OS and instead
-        // simply always called `rand::thread_rng().gen()` twice. In #31356 it
-        // was discovered, however, that because we re-seed the thread-local RNG
-        // from the OS periodically that this can cause excessive slowdown when
-        // many hash maps are created on a thread. To solve this performance
-        // trap we cache the first set of randomly generated keys per-thread.
-        //
-        // Later in #36481 it was discovered that exposing a deterministic
-        // iteration order allows a form of DOS attack. To counter that we
-        // increment one of the seeds on every RandomState creation, giving
-        // every corresponding HashMap a different iteration order.
-        thread_local!(static KEYS: Cell<(u64, u64)> = {
-            Cell::new(sys::hashmap_random_keys())
-        });
+        // Use a weak lang item to get random keys without a hard dependency
+        // on libstd.
+        #[cfg(not(stage0))]
+        #[allow(improper_ctypes)]
+        extern {
+            #[lang = "hashmap_random_keys"]
+            #[unwind(allowed)]
+            fn hashmap_random_keys() -> (u64, u64);
+        }
+        #[cfg(stage0)]
+        unsafe fn hashmap_random_keys() -> (u64, u64) { (0, 0) }
 
-        KEYS.with(|keys| {
-            let (k0, k1) = keys.get();
-            keys.set((k0.wrapping_add(1), k1));
-            RandomState { k0: k0, k1: k1 }
-        })
+        let (k0, k1) = unsafe { hashmap_random_keys() };
+        RandomState { k0: k0, k1: k1 }
     }
 }
 
@@ -2634,7 +2625,7 @@ impl BuildHasher for RandomState {
 /// not be relied upon over releases.
 ///
 /// [`RandomState`]: struct.RandomState.html
-/// [`Hasher`]: ../../hash/trait.Hasher.html
+/// [`Hasher`]: ../../../std/hash/trait.Hasher.html
 #[stable(feature = "hashmap_default_hasher", since = "1.13.0")]
 #[allow(deprecated)]
 #[derive(Clone, Debug)]
@@ -2768,11 +2759,12 @@ mod test_map {
     use super::HashMap;
     use super::Entry::{Occupied, Vacant};
     use super::RandomState;
-    use cell::RefCell;
+    use core::cell::RefCell;
     use rand::{thread_rng, Rng};
-    use realstd::collections::CollectionAllocErr::*;
-    use realstd::mem::size_of;
-    use realstd::usize;
+    use collections::CollectionAllocErr::*;
+    use std::mem::size_of;
+    use std::usize;
+    use vec::Vec;
 
     #[test]
     fn test_zero_capacities() {
diff --git a/src/libstd/collections/hash/mod.rs b/src/liballoc/collections/hash/mod.rs
similarity index 100%
rename from src/libstd/collections/hash/mod.rs
rename to src/liballoc/collections/hash/mod.rs
diff --git a/src/libstd/collections/hash/set.rs b/src/liballoc/collections/hash/set.rs
similarity index 99%
rename from src/libstd/collections/hash/set.rs
rename to src/liballoc/collections/hash/set.rs
index 5ac3e8f9cf7d3..f9590d49cf068 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/liballoc/collections/hash/set.rs
@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use borrow::Borrow;
-use fmt;
-use hash::{Hash, BuildHasher};
-use iter::{Chain, FromIterator, FusedIterator};
-use ops::{BitOr, BitAnd, BitXor, Sub};
+use core::borrow::Borrow;
+use core::fmt;
+use core::hash::{Hash, BuildHasher};
+use core::iter::{Chain, FromIterator, FusedIterator};
+use core::ops::{BitOr, BitAnd, BitXor, Sub};
 
 use super::Recover;
 use super::map::{self, HashMap, Keys, RandomState};
@@ -1403,6 +1403,7 @@ fn assert_covariance() {
 mod test_set {
     use super::HashSet;
     use super::super::map::RandomState;
+    use vec::Vec;
 
     #[test]
     fn test_zero_capacities() {
@@ -1712,7 +1713,7 @@ mod test_set {
 
     #[test]
     fn test_replace() {
-        use hash;
+        use core::hash;
 
         #[derive(Debug)]
         struct Foo(&'static str, i32);
diff --git a/src/libstd/collections/hash/table.rs b/src/liballoc/collections/hash/table.rs
similarity index 99%
rename from src/libstd/collections/hash/table.rs
rename to src/liballoc/collections/hash/table.rs
index 2b319186a8db2..16047dcdb7a92 100644
--- a/src/libstd/collections/hash/table.rs
+++ b/src/liballoc/collections/hash/table.rs
@@ -10,13 +10,13 @@
 
 use alloc::{Global, Alloc, Layout, LayoutErr, handle_alloc_error};
 use collections::CollectionAllocErr;
-use hash::{BuildHasher, Hash, Hasher};
-use marker;
-use mem::{size_of, needs_drop};
-use mem;
-use ops::{Deref, DerefMut};
-use ptr::{self, Unique, NonNull};
-use hint;
+use core::hash::{BuildHasher, Hash, Hasher};
+use core::marker;
+use core::mem::{size_of, needs_drop};
+use core::mem;
+use core::ops::{Deref, DerefMut};
+use core::ptr::{self, Unique, NonNull};
+use core::hint;
 
 use self::BucketState::*;
 
diff --git a/src/liballoc/collections/mod.rs b/src/liballoc/collections/mod.rs
index 96e0eb633b2f5..9a19feef23438 100644
--- a/src/liballoc/collections/mod.rs
+++ b/src/liballoc/collections/mod.rs
@@ -14,6 +14,7 @@
 
 pub mod binary_heap;
 mod btree;
+mod hash;
 pub mod linked_list;
 pub mod vec_deque;
 
@@ -31,6 +32,20 @@ pub mod btree_set {
     pub use super::btree::set::*;
 }
 
+#[unstable(feature = "alloc_hashmap", reason = "HashMap in liballoc is unstable", issue="0")]
+pub mod hash_map {
+    //! A hash map implemented with linear probing and Robin Hood bucket stealing.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::hash::map::*;
+}
+
+#[unstable(feature = "alloc_hashmap", reason = "HashMap in liballoc is unstable", issue="0")]
+pub mod hash_set {
+    //! A hash set implemented as a `HashMap` where the value is `()`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::hash::set::*;
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use self::binary_heap::BinaryHeap;
@@ -43,6 +58,14 @@ pub use self::btree_map::BTreeMap;
 #[doc(no_inline)]
 pub use self::btree_set::BTreeSet;
 
+#[unstable(feature = "alloc_hashmap", reason = "HashMap in liballoc is unstable", issue="0")]
+#[doc(no_inline)]
+pub use self::hash_map::HashMap;
+
+#[unstable(feature = "alloc_hashmap", reason = "HashMap in liballoc is unstable", issue="0")]
+#[doc(no_inline)]
+pub use self::hash_set::HashSet;
+
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use self::linked_list::LinkedList;
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 493448eaf88fa..e650cbd9b8b0b 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -69,7 +69,7 @@
        html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
        html_root_url = "https://doc.rust-lang.org/nightly/",
        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
-       test(no_crate_inject, attr(allow(unused_variables), deny(warnings))))]
+       test(no_crate_inject, attr(allow(unused_variables, unused_mut), deny(warnings))))]
 #![no_std]
 #![needs_allocator]
 #![deny(missing_debug_implementations)]
@@ -122,6 +122,8 @@
 #![feature(inclusive_range_methods)]
 #![feature(rustc_const_unstable)]
 #![feature(const_vec_new)]
+#![feature(unwind_attributes)]
+#![feature(hashmap_internals)]
 
 #![cfg_attr(not(test), feature(fn_traits, i128))]
 #![cfg_attr(test, feature(test))]
diff --git a/src/librustc/middle/lang_items.rs b/src/librustc/middle/lang_items.rs
index fe676919a7d14..c6046c809fb59 100644
--- a/src/librustc/middle/lang_items.rs
+++ b/src/librustc/middle/lang_items.rs
@@ -355,6 +355,8 @@ language_item_table! {
     AlignOffsetLangItem,             "align_offset",            align_offset_fn;
 
     TerminationTraitLangItem,        "termination",             termination;
+
+    HashMapRandomKeysLangItem,       "hashmap_random_keys",     hashmap_random_keys;
 }
 
 impl<'a, 'tcx, 'gcx> TyCtxt<'a, 'tcx, 'gcx> {
diff --git a/src/librustc/middle/weak_lang_items.rs b/src/librustc/middle/weak_lang_items.rs
index 180e75df1a66e..fce42bf47990e 100644
--- a/src/librustc/middle/weak_lang_items.rs
+++ b/src/librustc/middle/weak_lang_items.rs
@@ -166,4 +166,5 @@ weak_lang_items! {
     eh_personality,     EhPersonalityLangItem,      rust_eh_personality;
     eh_unwind_resume,   EhUnwindResumeLangItem,     rust_eh_unwind_resume;
     oom,                OomLangItem,                rust_oom;
+    hashmap_random_keys,HashMapRandomKeysLangItem,  rust_hashmap_random_keys;
 }
diff --git a/src/libstd/collections/mod.rs b/src/libstd/collections.rs
similarity index 93%
rename from src/libstd/collections/mod.rs
rename to src/libstd/collections.rs
index 8d2c82bc0aa84..2aec29bc7d8c8 100644
--- a/src/libstd/collections/mod.rs
+++ b/src/libstd/collections.rs
@@ -431,27 +431,51 @@ pub use alloc_crate::collections::{LinkedList, VecDeque};
 pub use alloc_crate::collections::{binary_heap, btree_map, btree_set};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use alloc_crate::collections::{linked_list, vec_deque};
-
-#[stable(feature = "rust1", since = "1.0.0")]
-pub use self::hash_map::HashMap;
 #[stable(feature = "rust1", since = "1.0.0")]
-pub use self::hash_set::HashSet;
-
-#[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
-pub use alloc_crate::collections::CollectionAllocErr;
-
-mod hash;
+pub use alloc_crate::collections::{HashMap, HashSet};
 
+// We can't just re-export the modules directly since they are unstable in liballoc
 #[stable(feature = "rust1", since = "1.0.0")]
 pub mod hash_map {
     //! A hash map implemented with linear probing and Robin Hood bucket stealing.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub use super::hash::map::*;
+    pub use alloc_crate::collections::hash_map::*;
 }
-
 #[stable(feature = "rust1", since = "1.0.0")]
 pub mod hash_set {
     //! A hash set implemented as a `HashMap` where the value is `()`.
     #[stable(feature = "rust1", since = "1.0.0")]
-    pub use super::hash::set::*;
+    pub use alloc_crate::collections::hash_set::*;
+}
+
+#[unstable(feature = "try_reserve", reason = "new API", issue="48043")]
+pub use alloc_crate::collections::CollectionAllocErr;
+
+#[cfg(not(stage0))]
+#[cfg_attr(not(test), lang = "hashmap_random_keys")]
+#[cfg_attr(test, allow(dead_code))]
+fn hashmap_random_keys() -> (u64, u64) {
+    use sys;
+    use cell::Cell;
+
+    // Historically this function did not cache keys from the OS and instead
+    // simply always called `rand::thread_rng().gen()` twice. In #31356 it
+    // was discovered, however, that because we re-seed the thread-local RNG
+    // from the OS periodically that this can cause excessive slowdown when
+    // many hash maps are created on a thread. To solve this performance
+    // trap we cache the first set of randomly generated keys per-thread.
+    //
+    // Later in #36481 it was discovered that exposing a deterministic
+    // iteration order allows a form of DOS attack. To counter that we
+    // increment one of the seeds on every RandomState creation, giving
+    // every corresponding HashMap a different iteration order.
+    thread_local!(static KEYS: Cell<(u64, u64)> = {
+        Cell::new(sys::hashmap_random_keys())
+    });
+
+    KEYS.with(|keys| {
+        let (k0, k1) = keys.get();
+        keys.set((k0.wrapping_add(1), k1));
+        (k0, k1)
+    })
 }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index d73cb1f8349a6..b2ce6e2eaef40 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -264,7 +264,6 @@
 #![feature(fnbox)]
 #![feature(futures_api)]
 #![feature(generator_trait)]
-#![feature(hashmap_internals)]
 #![feature(int_error_internals)]
 #![feature(integer_atomics)]
 #![feature(into_cow)]
@@ -323,6 +322,7 @@
 #![feature(float_internals)]
 #![feature(panic_info_message)]
 #![feature(panic_implementation)]
+#![feature(alloc_hashmap)]
 
 #![default_lib_allocator]
 
diff --git a/src/test/ui/missing-allocator.rs b/src/test/ui/missing-allocator.rs
index 24282631b7eea..e49ecdef2a04f 100644
--- a/src/test/ui/missing-allocator.rs
+++ b/src/test/ui/missing-allocator.rs
@@ -23,4 +23,7 @@ fn panic(_: &core::panic::PanicInfo) -> ! {
 #[lang = "oom"]
 fn oom() {}
 
+#[lang = "hashmap_random_keys"]
+fn hashmap_random_keys() {}
+
 extern crate alloc;