diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4ba67719590..dbf56b7fba8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,11 +13,18 @@
 #### Other Tools
 
 ### Core library changes
-* `dart:async`
-  * Update `Stream.fromIterable` to send a done event after the the error when
+#### `dart:async`
+
+*   Update `Stream.fromIterable` to send a done event after the the error when
     the iterator's `moveNext` throws, and handle if the `current` getter throws.
     Issue [33431](http://dartbug.com/33431).
 
+#### `dart:core`
+
+*   Added missing methods to `UnmodifiableMapMixin`. Some maps intended to
+    be unmodifiable incorrectly allowed new methods added in Dart 2 to
+    succeed.
+
 ## 2.1.0-dev.2.0
 
 ### Tool Changes
diff --git a/sdk/lib/collection/maps.dart b/sdk/lib/collection/maps.dart
index 795a2e3cc5a..60f66e18cc0 100644
--- a/sdk/lib/collection/maps.dart
+++ b/sdk/lib/collection/maps.dart
@@ -282,6 +282,11 @@ abstract class _UnmodifiableMapMixin<K, V> implements Map<K, V> {
     throw new UnsupportedError("Cannot modify unmodifiable map");
   }
 
+  /** This operation is not supported by an unmodifiable map. */
+  void addEntries(Iterable<MapEntry<K, V>> entries) {
+    throw new UnsupportedError("Cannot modify unmodifiable map");
+  }
+
   /** This operation is not supported by an unmodifiable map. */
   void clear() {
     throw new UnsupportedError("Cannot modify unmodifiable map");
@@ -292,10 +297,25 @@ abstract class _UnmodifiableMapMixin<K, V> implements Map<K, V> {
     throw new UnsupportedError("Cannot modify unmodifiable map");
   }
 
+  /** This operation is not supported by an unmodifiable map. */
+  void removeWhere(bool test(K key, V value)) {
+    throw new UnsupportedError("Cannot modify unmodifiable map");
+  }
+
   /** This operation is not supported by an unmodifiable map. */
   V putIfAbsent(K key, V ifAbsent()) {
     throw new UnsupportedError("Cannot modify unmodifiable map");
   }
+
+  /** This operation is not supported by an unmodifiable map. */
+  V update(K key, V update(V value), {V ifAbsent()}) {
+    throw new UnsupportedError("Cannot modify unmodifiable map");
+  }
+
+  /** This operation is not supported by an unmodifiable map. */
+  void updateAll(V update(K key, V value)) {
+    throw new UnsupportedError("Cannot modify unmodifiable map");
+  }
 }
 
 /**
@@ -341,7 +361,7 @@ class MapView<K, V> implements Map<K, V> {
 
   Iterable<MapEntry<K, V>> get entries => _map.entries;
 
-  void addEntries(Iterable<Object> entries) {
+  void addEntries(Iterable<MapEntry<K, V>> entries) {
     _map.addEntries(entries);
   }
 
diff --git a/tests/corelib_2/corelib_2.status b/tests/corelib_2/corelib_2.status
index dda114ea207..c4bdc22c427 100644
--- a/tests/corelib_2/corelib_2.status
+++ b/tests/corelib_2/corelib_2.status
@@ -89,6 +89,7 @@ symbol_test/03: MissingCompileTimeError
 [ !$strong ]
 cast_test: SkipByDesign # Uses generic method parameters.
 iterable_where_type_test: SkipByDesign
+map_test: SkipByDesign
 regress_33166_test: SkipByDesign # Not a Dart 1 test
 
 [ $arch == simarmv5te && ($runtime == dart_precompiled || $runtime == vm) ]
diff --git a/tests/corelib_2/map_test.dart b/tests/corelib_2/map_test.dart
index 275b5e6525d..5c9e9a4833a 100644
--- a/tests/corelib_2/map_test.dart
+++ b/tests/corelib_2/map_test.dart
@@ -27,6 +27,7 @@ void main() {
   testMapLiteral();
   testNullValue();
   testTypes();
+  testUnmodifiableMaps();
 
   testWeirdStringKeys(new Map());
   testWeirdStringKeys(new Map<String, String>());
@@ -703,8 +704,7 @@ class Equalizer {
   int id;
   Equalizer(this.id);
   int get hashCode => id;
-  bool operator ==(Object other) =>
-      other is Equalizer && id == (other as Equalizer).id;
+  bool operator ==(Object other) => other is Equalizer && id == other.id;
 }
 
 /**
@@ -721,7 +721,7 @@ class Vampire {
   // The double-fang operator falsely claims that a vampire is equal to
   // any of its sire's generation.
   bool operator ==(Object other) =>
-      other is Vampire && generation - 1 == (other as Vampire).generation;
+      other is Vampire && generation - 1 == other.generation;
 }
 
 void testCustomMap<K, V>(Map<K, V> typedMap) {
@@ -1026,3 +1026,21 @@ void testTypeAnnotations(Map<int, int> map) {
   Expect.equals(103, map.remove(0x20000000000000));
   testLength(1, map);
 }
+
+void testUnmodifiableMaps() {
+  void checkUnmodifiable(Map<int, int> map) {
+    Expect.throws(() => map[0] = 0);
+    Expect.throws(() => map.addAll({0: 0}));
+    Expect.throws(() => map.addEntries({0: 0}.entries));
+    Expect.throws(() => map.clear());
+    Expect.throws(() => map.putIfAbsent(0, () => 0));
+    Expect.throws(() => map.remove(0));
+    Expect.throws(() => map.removeWhere((k, v) => true));
+    Expect.throws(() => map.update(0, (v) => v, ifAbsent: () => 0));
+    Expect.throws(() => map.updateAll((k, v) => v));
+  }
+
+  checkUnmodifiable(const {1: 1});
+  checkUnmodifiable(Map.unmodifiable({1: 1}));
+  checkUnmodifiable(UnmodifiableMapView({1: 1}));
+}