diff --git a/src/api/time/TimeAPI.js b/src/api/time/TimeAPI.js
index 8d73a99722..18c26fc99d 100644
--- a/src/api/time/TimeAPI.js
+++ b/src/api/time/TimeAPI.js
@@ -239,7 +239,13 @@ define(['EventEmitter'], function (EventEmitter) {
      * @method timeSystem
      */
     TimeAPI.prototype.timeSystem = function (timeSystemOrKey, bounds) {
-        if (arguments.length >= 2) {
+        if (arguments.length >= 1) {
+            if (arguments.length === 1 && !this.activeClock) {
+                throw new Error(
+                    "Must specify bounds when changing time system without " +
+                    "an active clock."
+                );
+            }
             var timeSystem;
 
             if (timeSystemOrKey === undefined) {
@@ -274,10 +280,10 @@ define(['EventEmitter'], function (EventEmitter) {
              * Time System
              * */
             this.emit('timeSystem', this.system);
-            this.bounds(bounds);
+            if (bounds) {
+                this.bounds(bounds);
+            }
 
-        } else if (arguments.length === 1) {
-            throw new Error('Must set bounds when changing time system');
         }
 
         return this.system;
diff --git a/src/api/time/TimeAPISpec.js b/src/api/time/TimeAPISpec.js
index 1ea7c4b219..6efbbfd490 100644
--- a/src/api/time/TimeAPISpec.js
+++ b/src/api/time/TimeAPISpec.js
@@ -25,6 +25,8 @@ define(['./TimeAPI'], function (TimeAPI) {
         var api,
             timeSystemKey,
             timeSystem,
+            clockKey,
+            clock,
             bounds,
             eventListener,
             toi;
@@ -33,7 +35,15 @@ define(['./TimeAPI'], function (TimeAPI) {
             api = new TimeAPI();
             timeSystemKey = "timeSystemKey";
             timeSystem = {key: timeSystemKey};
-            bounds = {start: 0, end: 0};
+            clockKey = "someClockKey";
+            clock = jasmine.createSpyObj("clock", [
+                "on",
+                "off",
+                "currentValue"
+            ]);
+            clock.currentValue.andReturn(100);
+            clock.key = clockKey;
+            bounds = {start: 0, end: 1};
             eventListener = jasmine.createSpy("eventListener");
             toi = 111;
         });
@@ -74,11 +84,23 @@ define(['./TimeAPI'], function (TimeAPI) {
 
         it("Disallows setting of time system without bounds", function () {
             api.addTimeSystem(timeSystem);
-            expect(api.timeSystem()).not.toBe(timeSystemKey);
+            expect(api.timeSystem()).not.toBe(timeSystem);
             expect(function () {
                 api.timeSystem(timeSystemKey);
             }).toThrow();
-            expect(api.timeSystem()).not.toBe(timeSystemKey);
+            expect(api.timeSystem()).not.toBe(timeSystem);
+        });
+
+        it("allows setting of timesystem without bounds with clock", function () {
+            api.addTimeSystem(timeSystem);
+            api.addClock(clock);
+            api.clock(clockKey, {start: 0, end: 1})
+            expect(api.timeSystem()).not.toBe(timeSystem);
+            expect(function () {
+                api.timeSystem(timeSystemKey);
+            }).not.toThrow();
+            expect(api.timeSystem()).toBe(timeSystem);
+
         });
 
         it("Emits an event when time system changes", function () {