diff --git a/deps/chakrashim/include/v8.h b/deps/chakrashim/include/v8.h
index 057cd22b589..b16200c5bf9 100644
--- a/deps/chakrashim/include/v8.h
+++ b/deps/chakrashim/include/v8.h
@@ -1117,10 +1117,7 @@ class V8_EXPORT Value : public Data {
   bool IsFloat32Array() const;
   bool IsFloat64Array() const;
   bool IsDataView() const;
-  bool IsSharedArrayBuffer() const {
-    // CHAKRA-TODO Not implemented
-    return false;
-  }
+  bool IsSharedArrayBuffer() const;
   bool IsMapIterator() const;
   bool IsSetIterator() const;
   bool IsMap() const;
diff --git a/deps/chakrashim/lib/chakra_shim.js b/deps/chakrashim/lib/chakra_shim.js
index b8531358dcc..b92c622fcaa 100644
--- a/deps/chakrashim/lib/chakra_shim.js
+++ b/deps/chakrashim/lib/chakra_shim.js
@@ -30,11 +30,6 @@
   const Object_setPrototypeOf = Object.setPrototypeOf;
   const Reflect_apply = Reflect.apply;
   const Reflect_construct = Reflect.construct;
-  const Map_keys = Map.prototype.keys;
-  const Map_values = Map.prototype.values;
-  const Map_entries = Map.prototype.entries;
-  const Set_entries = Set.prototype.entries;
-  const Set_values = Set.prototype.values;
   const Symbol_keyFor = Symbol.keyFor;
   const Symbol_for = Symbol.for;
   const Global_ParseInt = parseInt;
@@ -324,41 +319,6 @@
     Error.captureStackTrace = captureStackTrace;
   }
 
-  const mapIteratorProperty = 'MapIteratorIndicator';
-  function patchMapIterator() {
-    const originalMapMethods = [];
-    originalMapMethods.push(['entries', Map_entries]);
-    originalMapMethods.push(['values', Map_values]);
-    originalMapMethods.push(['keys', Map_keys]);
-
-    originalMapMethods.forEach(function(pair) {
-      Map.prototype[pair[0]] = function() {
-        const result = pair[1].apply(this);
-        Object_defineProperty(
-          result, mapIteratorProperty,
-          { value: true, enumerable: false, writable: false });
-        return result;
-      };
-    });
-  }
-
-  const setIteratorProperty = 'SetIteratorIndicator';
-  function patchSetIterator() {
-    const originalSetMethods = [];
-    originalSetMethods.push(['entries', Set_entries]);
-    originalSetMethods.push(['values', Set_values]);
-
-    originalSetMethods.forEach(function(pair) {
-      Set.prototype[pair[0]] = function() {
-        const result = pair[1].apply(this);
-        Object_defineProperty(
-          result, setIteratorProperty,
-          { value: true, enumerable: false, writable: false });
-        return result;
-      };
-    });
-  }
-
   // Ensure global Debug object if not already exists, and patch it.
   function ensureDebug(otherGlobal) {
     if (!global.Debug) {
@@ -535,19 +495,19 @@
       return captureStackTrace({}, undefined)();
     };
 
-    utils.isMapIterator = function(value) {
-      return value[mapIteratorProperty] === true;
-    };
-
-    utils.isSetIterator = function(value) {
-      return value[setIteratorProperty] === true;
-    };
-
     function compareType(o, expectedType) {
       return Object_prototype_toString.call(o) === '[object ' +
             expectedType + ']';
     }
 
+    utils.isMapIterator = function(obj) {
+      return compareType(obj, 'Map Iterator');
+    };
+
+    utils.isSetIterator = function(obj) {
+      return compareType(obj, 'Set Iterator');
+    };
+
     utils.isBooleanObject = function(obj) {
       return compareType(obj, 'Boolean');
     };
@@ -627,6 +587,10 @@
       return compareType(obj, 'String') || compareType(obj, 'Symbol');
     };
 
+    utils.isSharedArrayBuffer = function(obj) {
+      return compareType(obj, 'SharedArrayBuffer');
+    };
+
     utils.getSymbolKeyFor = function(symbol) {
       return Symbol_keyFor(symbol);
     };
@@ -707,8 +671,6 @@
 
   patchErrorTypes();
   patchErrorStack();
-  patchMapIterator();
-  patchSetIterator();
 
   patchUtils(keepAlive);
 });
diff --git a/deps/chakrashim/src/jsrtcachedpropertyidref.inc b/deps/chakrashim/src/jsrtcachedpropertyidref.inc
index d50b369f42b..4f542b5ec1a 100644
--- a/deps/chakrashim/src/jsrtcachedpropertyidref.inc
+++ b/deps/chakrashim/src/jsrtcachedpropertyidref.inc
@@ -161,6 +161,7 @@ DEF_IS_TYPE(isWeakMap)
 DEF_IS_TYPE(isWeakSet)
 DEF_IS_TYPE(isSymbolObject)
 DEF_IS_TYPE(isName)
+DEF_IS_TYPE(isSharedArrayBuffer)
 
 
 #undef DEF
diff --git a/deps/chakrashim/src/v8value.cc b/deps/chakrashim/src/v8value.cc
index 6232bdfdf08..2dc76a297fc 100644
--- a/deps/chakrashim/src/v8value.cc
+++ b/deps/chakrashim/src/v8value.cc
@@ -179,6 +179,7 @@ IS_TYPE_FUNCTION(IsWeakMap, isWeakMap)
 IS_TYPE_FUNCTION(IsWeakSet, isWeakSet)
 IS_TYPE_FUNCTION(IsSymbolObject, isSymbolObject)
 IS_TYPE_FUNCTION(IsName, isName)
+IS_TYPE_FUNCTION(IsSharedArrayBuffer, isSharedArrayBuffer)
 
 MaybeLocal<Boolean> Value::ToBoolean(Local<Context> context) const {
   JsValueRef value;
diff --git a/lib/internal/bootstrap_node.js b/lib/internal/bootstrap_node.js
index 49ebb849353..1c3fd006336 100644
--- a/lib/internal/bootstrap_node.js
+++ b/lib/internal/bootstrap_node.js
@@ -26,14 +26,14 @@
 
     if (process.jsEngine === 'chakracore') {
       // This file contains the V8-specific "%<function>" syntax for accessing
-      // private functions.  This is not supported on ChakraCore and causes a
-      // parser failure.  Inject a cache entry to prevent the file from being
-      // parsed.
+      // private functions. This is not supported on ChakraCore and causes a
+      // parser failure. Inject a cache entry to prevent the file from being
+      // parsed. Return an array to mimmick behavior (required by util.inspect)
       NativeModule._cache['internal/v8'] = {
         loaded: true,
         exports: {
-          previewMapIterator: function() {},
-          previewSetIterator: function() {},
+          previewMapIterator: function() { return []; },
+          previewSetIterator: function() { return []; },
         },
       };
     }
diff --git a/test/parallel/test-util-types.js b/test/parallel/test-util-types.js
index f9211ddf420..7b20d966a10 100644
--- a/test/parallel/test-util-types.js
+++ b/test/parallel/test-util-types.js
@@ -49,7 +49,9 @@ for (const [ value, _method ] of [
                           { value: 'foo' }) ],
   [ new DataView(new ArrayBuffer()) ],
   [ new SharedArrayBuffer() ],
-  [ new Proxy({}, {}), 'isProxy' ],
+  // Node-ChakraCore does not support util.types.isProxy() due to
+  // Microsoft/ChakraCore#950 and node/node-chakracore#488
+  !common.isChakraEngine ? [ new Proxy({}, {}), 'isProxy' ] : [ new Date() ],
   [ new WebAssembly.Module(wasmBuffer), 'isWebAssemblyCompiledModule' ],
 ]) {
   const method = _method || `is${value.constructor.name}`;