diff --git a/spec/core/ClockSpec.js b/spec/core/ClockSpec.js
index 18d281bf..5374d899 100644
--- a/spec/core/ClockSpec.js
+++ b/spec/core/ClockSpec.js
@@ -417,6 +417,8 @@ describe("Clock (acceptance)", function() {
 
     clock.install().mockDate();
 
+    expect(new global.Date() instanceof global.Date).toBe(true);
+
     var now = new global.Date().getTime();
 
     clock.tick(50);
@@ -443,6 +445,8 @@ describe("Clock (acceptance)", function() {
 
     clock.install().mockDate(baseTime);
 
+    expect(new global.Date() instanceof global.Date).toBe(true);
+
     var now = new global.Date().getTime();
 
     expect(now).toEqual(baseTime.getTime());
diff --git a/src/core/MockDate.js b/src/core/MockDate.js
index db347bbe..e7914fb2 100644
--- a/src/core/MockDate.js
+++ b/src/core/MockDate.js
@@ -61,6 +61,7 @@ getJasmineRequireObj().MockDate = function() {
     }
 
     function createDateProperties() {
+      FakeDate.prototype = GlobalDate.prototype;
 
       FakeDate.now = function() {
         if (GlobalDate.now) {