diff --git a/packages/babel-plugin-flow-runtime/src/ConversionContext.js b/packages/babel-plugin-flow-runtime/src/ConversionContext.js
index d81d33b6..3d651406 100644
--- a/packages/babel-plugin-flow-runtime/src/ConversionContext.js
+++ b/packages/babel-plugin-flow-runtime/src/ConversionContext.js
@@ -32,6 +32,7 @@ export default class ConversionContext {
   shouldAssert: boolean = true;
   shouldWarn: boolean = false;
   shouldAnnotate: boolean = true;
+  shouldReferenceGlobalTypeValues: boolean = false;
   optInOnly: boolean = false;
   isAnnotating: boolean = false;
   suppressCommentPatterns: RegExp[] = [/\$FlowFixMe/];
diff --git a/packages/babel-plugin-flow-runtime/src/__tests__/__fixtures__/bugs/177-map-class-property-transform-runtime.js b/packages/babel-plugin-flow-runtime/src/__tests__/__fixtures__/bugs/177-map-class-property-transform-runtime.js
new file mode 100644
index 00000000..3c9536f2
--- /dev/null
+++ b/packages/babel-plugin-flow-runtime/src/__tests__/__fixtures__/bugs/177-map-class-property-transform-runtime.js
@@ -0,0 +1,63 @@
+/* @flow */
+
+export const input = `
+  class Foo {
+    bar: Map<string, any> = new Map();
+
+    getValue(name: string) {
+      return this.bar.get(name);
+    }
+  }
+`;
+
+export const expected = `
+  import t from "flow-runtime";
+
+  class Foo {
+    @t.decorate(t.ref(Map, t.string(), t.any()))
+    bar = new Map();
+
+    getValue(name) {
+      let _nameType = t.string();
+      t.param("name", _nameType).assert(name);
+      return this.bar.get(name);
+    }
+  }
+`;
+
+export const annotated = `
+  import t from "flow-runtime";
+
+  @t.annotate(t.class(
+    "Foo",
+    t.property("bar", t.ref("Map", t.string(), t.any())),
+    t.method("getValue", t.param("name", t.string()))
+  ))
+  class Foo {
+    bar = new Map();
+
+    getValue(name) {
+      return this.bar.get(name);
+    }
+  }
+`;
+
+export const combined = `
+  import t from "flow-runtime";
+
+  @t.annotate(t.class(
+    "Foo",
+    t.property("bar", t.ref("Map", t.string(), t.any())),
+    t.method("getValue", t.param("name", t.string()))
+  ))
+  class Foo {
+    @t.decorate(t.ref(Map, t.string(), t.any()))
+    bar = new Map();
+
+    getValue(name) {
+      let _nameType = t.string();
+      t.param("name", _nameType).assert(name);
+      return this.bar.get(name);
+    }
+  }
+`;
diff --git a/packages/babel-plugin-flow-runtime/src/convert.js b/packages/babel-plugin-flow-runtime/src/convert.js
index d273df80..56639b7a 100644
--- a/packages/babel-plugin-flow-runtime/src/convert.js
+++ b/packages/babel-plugin-flow-runtime/src/convert.js
@@ -13,6 +13,7 @@ export type Converter = (context: ConversionContext, path: NodePath) => Node;
 export type ConverterDict = {[name: string]: Converter};
 
 const converters: ConverterDict = {};
+const GLOBAL_TYPE_VALUE_REFS = ['Date', 'Map', 'Promise', 'Set'];
 
 function getPropertyName(path: NodePath): string {
   if (path.get('key').isIdentifier()) return path.node.key.name;
@@ -639,6 +640,12 @@ converters.GenericTypeAnnotation = (context: ConversionContext, path: NodePath):
     if (flowTypeName) {
       return context.call(flowTypeName, ...typeParameters);
     }
+    else if (
+      context.shouldReferenceGlobalTypeValues &&
+      GLOBAL_TYPE_VALUE_REFS.indexOf(name) !== -1
+    ) {
+      return context.call('ref', subject, ...typeParameters);
+    }
     else {
       return context.call('ref', t.stringLiteral(name), ...typeParameters);
     }
diff --git a/packages/babel-plugin-flow-runtime/src/transformVisitors.js b/packages/babel-plugin-flow-runtime/src/transformVisitors.js
index e88d0f71..f99c16d5 100644
--- a/packages/babel-plugin-flow-runtime/src/transformVisitors.js
+++ b/packages/babel-plugin-flow-runtime/src/transformVisitors.js
@@ -813,7 +813,7 @@ export default function transformVisitors (context: ConversionContext): Object {
             null,
             [],
             t.blockStatement([
-              t.returnStatement(convert(context, typeAnnotation))
+              t.returnStatement(convertClassPropertyAnnotation(context, typeAnnotation))
             ])
           )
         ];
@@ -827,12 +827,12 @@ export default function transformVisitors (context: ConversionContext): Object {
       }
       else if (context.shouldWarn) {
         decorator = t.decorator(
-          context.call('decorate', convert(context, typeAnnotation), t.booleanLiteral(false))
+          context.call('decorate', convertClassPropertyAnnotation(context, typeAnnotation), t.booleanLiteral(false))
         );
       }
       else {
         decorator = t.decorator(
-          context.call('decorate', convert(context, typeAnnotation))
+          context.call('decorate', convertClassPropertyAnnotation(context, typeAnnotation))
         );
       }
       if (!path.has('decorators')) {
@@ -867,6 +867,17 @@ function isReactComponentClass (path: NodePath): boolean {
   }
 }
 
+function convertClassPropertyAnnotation (context: ConversionContext, typeAnnotation: NodePath): Node {
+  const previous = context.shouldReferenceGlobalTypeValues;
+  context.shouldReferenceGlobalTypeValues = true;
+  try {
+    return convert(context, typeAnnotation);
+  }
+  finally {
+    context.shouldReferenceGlobalTypeValues = previous;
+  }
+}
+
 const supportedIterableNames = {
   Generator: true,
   Iterable: true,
diff --git a/packages/flow-runtime/src/registerTypePredicates.js b/packages/flow-runtime/src/registerTypePredicates.js
index beefe65b..5209fcee 100644
--- a/packages/flow-runtime/src/registerTypePredicates.js
+++ b/packages/flow-runtime/src/registerTypePredicates.js
@@ -4,7 +4,9 @@ import type TypeContext from './TypeContext';
 
 export default function registerTypePredicates (context: TypeContext) {
   context.setPredicate('Array', (input: any) => Array.isArray(input));
-  context.setPredicate('Map', (input: any) => input instanceof Map);
+  context.setPredicate('Map', (input: any) => {
+    return input instanceof Map || Object.prototype.toString.call(input) === '[object Map]';
+  });
   context.setPredicate('Set', (input: any) => input instanceof Set);
   context.setPredicate('Promise', (input: any) => {
     if (input instanceof Promise) {
diff --git a/packages/flow-runtime/src/typed.test.js b/packages/flow-runtime/src/typed.test.js
index d2eb3380..3d7f4f8b 100644
--- a/packages/flow-runtime/src/typed.test.js
+++ b/packages/flow-runtime/src/typed.test.js
@@ -1,5 +1,6 @@
 /* @flow */
 import {ok, equal, throws} from 'assert';
+import {runInNewContext} from 'vm';
 
 import t from './globalContext';
 
@@ -259,6 +260,13 @@ describe('Typed API', () => {
 
   });
 
+  it('should accept a Map from another realm', () => {
+    const type = t.ref(Map, t.string(), t.number());
+    const map = runInNewContext('new Map([["valid", 123]])');
+
+    ok(type.accepts(map));
+  });
+
   it('should make a simple function type', () => {
     const type = t.fn(
       t.param('input', t.boolean()),
@@ -558,4 +566,4 @@ describe('Typed API', () => {
       ))
     );
   });
-});
\ No newline at end of file
+});