diff --git a/apps/tests/observable-tests.ts b/apps/tests/observable-tests.ts
index b0a29ddf4..1cbb6e702 100644
--- a/apps/tests/observable-tests.ts
+++ b/apps/tests/observable-tests.ts
@@ -478,4 +478,16 @@ export var test_ObservablesCreatedWithJSON_shouldNotInterfereWithOneAnother = fu
     TKUnit.wait(0.1);
     TKUnit.assert(propName2 === "property2", "propName2 should be 'property2'");
     TKUnit.assert(newValue2 === 20, "newValue2 should be 20");
-};
\ No newline at end of file
+};
+
+export function test_ObservablesCreatedWithJSON_shouldNotEmitTwoTimesPropertyChangeEvent() {
+    var testObservable = new observable.Observable({ "property1": 1 });
+    var propertyChangeCounter = 0;
+    var propertyChangeHandler = function (args) {
+        propertyChangeCounter++;
+    }
+    testObservable.on(observable.Observable.propertyChangeEvent, propertyChangeHandler);
+    testObservable.set("property1", 2);
+
+    TKUnit.assertEqual(propertyChangeCounter, 1, "PropertyChange event should be fired only once for a single change.");
+}
\ No newline at end of file
diff --git a/data/observable/observable.ts b/data/observable/observable.ts
index e677fede6..f97302564 100644
--- a/data/observable/observable.ts
+++ b/data/observable/observable.ts
@@ -121,11 +121,19 @@ export class Observable implements definition.Observable {
         return this[name];
     }
 
+    private disableNotifications = false;
+
     public _setCore(data: definition.PropertyChangeData) {
+        this.disableNotifications = true;
         this[data.propertyName] = data.value;
+        this.disableNotifications = false;
     }
 
     public notify<T extends definition.EventData>(data: T) {
+        if (this.disableNotifications) {
+            return;
+        }
+
         var observers = this._getEventList(data.eventName);
         if (!observers) {
             return;
@@ -134,7 +142,7 @@ export class Observable implements definition.Observable {
         var i;
         var entry: ListenerEntry;
         var observersLength = observers.length;
-        for (i = observersLength - 1; i >= 0 ; i--) {
+        for (i = observersLength - 1; i >= 0; i--) {
             entry = observers[i];
             if (entry.thisArg) {
                 entry.callback.apply(entry.thisArg, [data]);