diff --git a/packages/flow-runtime/src/registerTypePredicates.js b/packages/flow-runtime/src/registerTypePredicates.js
index beefe65b..1e958185 100644
--- a/packages/flow-runtime/src/registerTypePredicates.js
+++ b/packages/flow-runtime/src/registerTypePredicates.js
@@ -2,9 +2,15 @@
 
 import type TypeContext from './TypeContext';
 
+const objectToString = Object.prototype.toString;
+
+const isMap = (input: any): boolean => {
+  return input instanceof Map || objectToString.call(input) === '[object Map]';
+};
+
 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', isMap);
   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..e10133be 100644
--- a/packages/flow-runtime/src/typed.test.js
+++ b/packages/flow-runtime/src/typed.test.js
@@ -3,6 +3,8 @@ import {ok, equal, throws} from 'assert';
 
 import t from './globalContext';
 
+const BabelRuntimeMap: any = require('babel-runtime/core-js/map').default; // eslint-disable-line import/no-extraneous-dependencies
+
 const no = (input: any): any => equal(Boolean(input), false);
 
 describe('Typed API', () => {
@@ -259,6 +261,22 @@ describe('Typed API', () => {
 
   });
 
+  it('should accept a babel-runtime Map<string, number>', () => {
+    const RuntimeMap = BabelRuntimeMap;
+    const type = t.ref(Map, t.string(), t.number());
+
+    const valid = new RuntimeMap([
+      ['valid', 123]
+    ]);
+    ok(type.accepts(valid));
+
+    const invalid = new RuntimeMap([
+      ['valid', 123],
+      ['notvalid', false]
+    ]);
+    no(type.accepts(invalid));
+  });
+
   it('should make a simple function type', () => {
     const type = t.fn(
       t.param('input', t.boolean()),
@@ -558,4 +576,4 @@ describe('Typed API', () => {
       ))
     );
   });
-});
\ No newline at end of file
+});