diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 708b3b70..58887e75 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -60,7 +60,7 @@ var getJasmineRequireObj = (function(jasmineGlobal) {
     j$.Any = jRequire.Any(j$);
     j$.Anything = jRequire.Anything(j$);
     j$.CallTracker = jRequire.CallTracker(j$);
-    j$.MockDate = jRequire.MockDate();
+    j$.MockDate = jRequire.MockDate(j$);
     j$.getClearStack = jRequire.clearStack(j$);
     j$.Clock = jRequire.Clock();
     j$.DelayedFunctionScheduler = jRequire.DelayedFunctionScheduler(j$);
@@ -7774,7 +7774,7 @@ getJasmineRequireObj().toThrowMatching = function(j$) {
   return toThrowMatching;
 };
 
-getJasmineRequireObj().MockDate = function() {
+getJasmineRequireObj().MockDate = function(j$) {
   function MockDate(global) {
     var self = this;
     var currentTime = 0;
@@ -7792,6 +7792,14 @@ getJasmineRequireObj().MockDate = function() {
       if (mockDate instanceof GlobalDate) {
         currentTime = mockDate.getTime();
       } else {
+        if (!j$.util.isUndefined(mockDate)) {
+          j$.getEnv().deprecated(
+            'The argument to jasmine.clock().mockDate(), if specified, ' +
+              'should be a Date instance. Passing anything other than a Date ' +
+              'will be treated as an error in a future release.'
+          );
+        }
+
         currentTime = new GlobalDate().getTime();
       }
 
diff --git a/spec/core/ClockSpec.js b/spec/core/ClockSpec.js
index 2aba566b..126fe8ca 100644
--- a/spec/core/ClockSpec.js
+++ b/spec/core/ClockSpec.js
@@ -950,6 +950,28 @@ describe('Clock (acceptance)', function() {
     expect(timeoutDate).toEqual(baseTime.getTime() + 150);
   });
 
+  it('logs a deprecation when mockDate is called with a non-Date', function() {
+    var delayedFunctionScheduler = new jasmineUnderTest.DelayedFunctionScheduler(),
+      global = { Date: Date },
+      mockDate = new jasmineUnderTest.MockDate(global),
+      clock = new jasmineUnderTest.Clock(
+        { setTimeout: setTimeout },
+        function() {
+          return delayedFunctionScheduler;
+        },
+        mockDate
+      ),
+      env = jasmineUnderTest.getEnv();
+
+    spyOn(env, 'deprecated');
+    clock.mockDate(12345);
+    expect(env.deprecated).toHaveBeenCalledWith(
+      'The argument to jasmine.clock().mockDate(), if specified, should be ' +
+        'a Date instance. Passing anything other than a Date will be ' +
+        'treated as an error in a future release.'
+    );
+  });
+
   it('mocks the Date object and updates the date per delayed function', function() {
     var delayedFunctionScheduler = new jasmineUnderTest.DelayedFunctionScheduler(),
       global = { Date: Date },
diff --git a/src/core/MockDate.js b/src/core/MockDate.js
index 7b642038..74a6956f 100644
--- a/src/core/MockDate.js
+++ b/src/core/MockDate.js
@@ -1,4 +1,4 @@
-getJasmineRequireObj().MockDate = function() {
+getJasmineRequireObj().MockDate = function(j$) {
   function MockDate(global) {
     var self = this;
     var currentTime = 0;
@@ -16,6 +16,14 @@ getJasmineRequireObj().MockDate = function() {
       if (mockDate instanceof GlobalDate) {
         currentTime = mockDate.getTime();
       } else {
+        if (!j$.util.isUndefined(mockDate)) {
+          j$.getEnv().deprecated(
+            'The argument to jasmine.clock().mockDate(), if specified, ' +
+              'should be a Date instance. Passing anything other than a Date ' +
+              'will be treated as an error in a future release.'
+          );
+        }
+
         currentTime = new GlobalDate().getTime();
       }
 
diff --git a/src/core/requireCore.js b/src/core/requireCore.js
index 1a2ee522..1b8b5238 100644
--- a/src/core/requireCore.js
+++ b/src/core/requireCore.js
@@ -38,7 +38,7 @@ var getJasmineRequireObj = (function(jasmineGlobal) {
     j$.Any = jRequire.Any(j$);
     j$.Anything = jRequire.Anything(j$);
     j$.CallTracker = jRequire.CallTracker(j$);
-    j$.MockDate = jRequire.MockDate();
+    j$.MockDate = jRequire.MockDate(j$);
     j$.getClearStack = jRequire.clearStack(j$);
     j$.Clock = jRequire.Clock();
     j$.DelayedFunctionScheduler = jRequire.DelayedFunctionScheduler(j$);