diff --git a/tests/app/app/app-new.css b/tests/app/app/app-new.css
new file mode 100644
index 000000000..2b3afb687
--- /dev/null
+++ b/tests/app/app/app-new.css
@@ -0,0 +1,3 @@
+Button, Label {
+    color: green;
+}
diff --git a/tests/app/app/app-new.scss b/tests/app/app/app-new.scss
new file mode 100644
index 000000000..2b3afb687
--- /dev/null
+++ b/tests/app/app/app-new.scss
@@ -0,0 +1,3 @@
+Button, Label {
+    color: green;
+}
diff --git a/tests/app/app/application.css b/tests/app/app/application.css
new file mode 100644
index 000000000..119b358a7
--- /dev/null
+++ b/tests/app/app/application.css
@@ -0,0 +1,3 @@
+Button, Label {
+    color: black;
+}
diff --git a/tests/app/app/mainPage.ts b/tests/app/app/mainPage.ts
index 70e2ce2e7..4c16fca02 100644
--- a/tests/app/app/mainPage.ts
+++ b/tests/app/app/mainPage.ts
@@ -2,6 +2,8 @@
 import * as trace from "tns-core-modules/trace";
 import * as tests from "../testRunner";
 
+let executeTests = true;
+
 trace.enable();
 trace.addCategories(trace.categories.Test + "," + trace.categories.Error);
 
@@ -21,6 +23,8 @@ function runTests() {
 
 export function onNavigatedTo(args) {
     args.object.off(Page.loadedEvent, onNavigatedTo);
-
-    runTests();
+    if (executeTests) {
+        executeTests = false;
+        runTests();
+    }
 }
diff --git a/tests/app/app/mainPage.xml b/tests/app/app/mainPage.xml
index bee9a71d8..7cead486d 100644
--- a/tests/app/app/mainPage.xml
+++ b/tests/app/app/mainPage.xml
@@ -1,3 +1,3 @@
 <Page navigatedTo="onNavigatedTo">
-    <Label text="Running non-UI tests..." />
+    <Label id="label" text="Running non-UI tests..." />
 </Page>
diff --git a/tests/app/livesync/livesync-tests.ts b/tests/app/livesync/livesync-tests.ts
new file mode 100644
index 000000000..8ae772203
--- /dev/null
+++ b/tests/app/livesync/livesync-tests.ts
@@ -0,0 +1,113 @@
+import * as app from "tns-core-modules/application/application";
+import * as frame from "tns-core-modules/ui/frame";
+import * as helper from "../ui/helper";
+import * as TKUnit from "../TKUnit";
+import { Color } from "tns-core-modules/color";
+import { parse } from "tns-core-modules/ui/builder";
+import { Page } from "tns-core-modules/ui/page";
+
+const appCssFileName = "./app/application.css";
+const appNewCssFileName = "./app/app-new.css";
+const appNewScssFileName = "./app/app-new.scss";
+const appJsFileName = "./app/app.js";
+const appTsFileName = "./app/app.ts";
+const mainPageCssFileName = "./app/main-page.css";
+const mainPageHtmlFileName = "./app/main-page.html";
+const mainPageXmlFileName = "./app/main-page.xml";
+
+const green = new Color("green");
+
+const mainPageTemplate = `
+    <Page>
+        <StackLayout>
+            <Label id="label" text="label"></Label>
+        </StackLayout>
+    </Page>`;
+
+const pageTemplate = `
+    <Page>
+        <StackLayout>
+            <Button id="button" text="button"></Button>
+        </StackLayout>
+    </Page>`;
+
+export function test_onLiveSync_HmrContext_AppStyle_AppNewCss() {
+    _test_onLiveSync_HmrContext_AppStyle(appNewCssFileName);
+}
+
+export function test_onLiveSync_HmrContext_AppStyle_AppNewScss() {
+    _test_onLiveSync_HmrContext_AppStyle(appNewScssFileName);
+}
+
+export function test_onLiveSync_HmrContext_ContextUndefined() {
+    _test_onLiveSync_HmrContext({ type: undefined, module: undefined });
+}
+
+export function test_onLiveSync_HmrContext_ModuleUndefined() {
+    _test_onLiveSync_HmrContext({ type: "script", module: undefined });
+}
+
+export function test_onLiveSync_HmrContext_Script_AppJs() {
+    _test_onLiveSync_HmrContext({ type: "script", module: appJsFileName });
+}
+
+export function test_onLiveSync_HmrContext_Script_AppTs() {
+    _test_onLiveSync_HmrContext({ type: "script", module: appTsFileName });
+}
+
+export function test_onLiveSync_HmrContext_Style_MainPageCss() {
+    _test_onLiveSync_HmrContext({ type: "style", module: mainPageCssFileName });
+}
+
+export function test_onLiveSync_HmrContext_Markup_MainPageHtml() {
+    _test_onLiveSync_HmrContext({ type: "markup", module: mainPageHtmlFileName });
+}
+
+export function test_onLiveSync_HmrContext_Markup_MainPageXml() {
+    _test_onLiveSync_HmrContext({ type: "markup", module: mainPageXmlFileName });
+}
+
+export function setUpModule() {
+    const mainPage = <Page>parse(mainPageTemplate);
+    helper.navigate(() => mainPage);
+}
+
+export function tearDown() {
+    app.setCssFileName(appCssFileName);
+}
+
+function _test_onLiveSync_HmrContext_AppStyle(styleFileName: string) {
+    const pageBeforeNavigation = helper.getCurrentPage();
+
+    const page = <Page>parse(pageTemplate);
+    helper.navigateWithHistory(() => page);
+    app.setCssFileName(styleFileName);
+
+    const pageBeforeLiveSync = helper.getCurrentPage();
+    global.__onLiveSync({ type: "style", module: styleFileName });
+
+    const pageAfterLiveSync = helper.getCurrentPage();
+    TKUnit.waitUntilReady(() => pageAfterLiveSync.getViewById("button").style.color.toString() === green.toString());
+
+    TKUnit.assertTrue(pageAfterLiveSync.frame.canGoBack(), "App styles NOT applied - livesync navigation executed!");
+    TKUnit.assertEqual(pageAfterLiveSync, pageBeforeLiveSync, "Pages are different - livesync navigation executed!");
+    TKUnit.assertTrue(pageAfterLiveSync._cssState.isSelectorsLatestVersionApplied(), "Latest selectors version NOT applied!");
+
+    helper.goBack();
+
+    const pageAfterNavigationBack = helper.getCurrentPage();
+    TKUnit.assertEqual(pageAfterNavigationBack.getViewById("label").style.color, green, "App styles NOT applied on back navigation!");
+    TKUnit.assertEqual(pageBeforeNavigation, pageAfterNavigationBack, "Pages are different - livesync navigation executed!");
+    TKUnit.assertTrue(pageAfterNavigationBack._cssState.isSelectorsLatestVersionApplied(), "Latest selectors version is NOT applied!");
+}
+
+function _test_onLiveSync_HmrContext(context: { type, module }) {
+    const page = <Page>parse(pageTemplate);
+    helper.navigateWithHistory(() => page);
+    global.__onLiveSync({ type: context.type, module: context.module });
+
+    TKUnit.waitUntilReady(() => !!frame.topmost());
+    const topmostFrame = frame.topmost();
+    TKUnit.waitUntilReady(() => topmostFrame.currentPage && topmostFrame.currentPage.isLoaded && !topmostFrame.canGoBack());
+    TKUnit.assertTrue(topmostFrame.currentPage.getViewById("label").isLoaded);
+}
\ No newline at end of file
diff --git a/tests/app/testRunner.ts b/tests/app/testRunner.ts
index a119642a0..b96bde95d 100644
--- a/tests/app/testRunner.ts
+++ b/tests/app/testRunner.ts
@@ -153,9 +153,6 @@ allTests["STYLE-PROPERTIES"] = stylePropertiesTests;
 import * as frameTests from "./ui/frame/frame-tests";
 allTests["FRAME"] = frameTests;
 
-import * as tabViewRootTests from "./ui/tab-view/tab-view-root-tests";
-allTests["TAB-VIEW-ROOT"] = tabViewRootTests;
-
 import * as viewTests from "./ui/view/view-tests";
 allTests["VIEW"] = viewTests;
 
@@ -255,6 +252,12 @@ allTests["SEARCH-BAR"] = searchBarTests;
 import * as navigationTests from "./navigation/navigation-tests";
 allTests["NAVIGATION"] = navigationTests;
 
+import * as livesyncTests from "./livesync/livesync-tests";
+allTests["LIVESYNC"] = livesyncTests;
+
+import * as tabViewRootTests from "./ui/tab-view/tab-view-root-tests";
+allTests["TAB-VIEW-ROOT"] = tabViewRootTests;
+
 import * as resetRootViewTests from "./ui/root-view/reset-root-view-tests";
 allTests["RESET-ROOT-VIEW"] = resetRootViewTests;
 
diff --git a/tns-core-modules/application/application-common.ts b/tns-core-modules/application/application-common.ts
index 32ab9dc04..3f0d0888c 100644
--- a/tns-core-modules/application/application-common.ts
+++ b/tns-core-modules/application/application-common.ts
@@ -32,7 +32,14 @@ export function hasLaunched(): boolean {
 
 export { Observable };
 
-import { UnhandledErrorEventData, iOSApplication, AndroidApplication, CssChangedEventData, LoadAppCSSEventData } from ".";
+import {
+    AndroidApplication,
+    CssChangedEventData,
+    getRootView,
+    iOSApplication,
+    LoadAppCSSEventData,
+    UnhandledErrorEventData
+} from "./application";
 
 export { UnhandledErrorEventData, CssChangedEventData, LoadAppCSSEventData };
 
@@ -70,10 +77,21 @@ export function setApplication(instance: iOSApplication | AndroidApplication): v
     app = instance;
 }
 
-export function livesync() {
+export function livesync(context?: HmrContext) {
     events.notify(<EventData>{ eventName: "livesync", object: app });
     const liveSyncCore = global.__onLiveSyncCore;
-    if (liveSyncCore) {
+    let reapplyAppCss = false
+
+    if (context) {
+        const fullFileName = getCssFileName();
+        const fileName = fullFileName.substring(0, fullFileName.lastIndexOf(".") + 1);
+        const extensions = ["css", "scss"];
+        reapplyAppCss = extensions.some(ext => context.module === fileName.concat(ext));
+    }
+
+    if (reapplyAppCss) {
+        getRootView()._onCssStateChange();
+    } else if (liveSyncCore) {
         liveSyncCore();
     }
 }
@@ -92,7 +110,7 @@ export function loadAppCss(): void {
         events.notify(<LoadAppCSSEventData>{ eventName: "loadAppCss", object: app, cssFile: getCssFileName() });
     } catch (e) {
         throw new Error(`The file ${getCssFileName()} couldn't be loaded! ` +
-           `You may need to register it inside ./app/vendor.ts.`);
+            `You may need to register it inside ./app/vendor.ts.`);
     }
 }
 
diff --git a/tns-core-modules/application/application.android.ts b/tns-core-modules/application/application.android.ts
index 0b33bba80..6d5166675 100644
--- a/tns-core-modules/application/application.android.ts
+++ b/tns-core-modules/application/application.android.ts
@@ -212,12 +212,12 @@ export function getNativeApplication(): android.app.Application {
     return nativeApp;
 }
 
-global.__onLiveSync = function () {
+global.__onLiveSync = function __onLiveSync(context?: HmrContext) {
     if (androidApp && androidApp.paused) {
         return;
     }
 
-    livesync();
+    livesync(context);
 };
 
 function initLifecycleCallbacks() {
diff --git a/tns-core-modules/application/application.ios.ts b/tns-core-modules/application/application.ios.ts
index 867f2ef6f..af6028cd4 100644
--- a/tns-core-modules/application/application.ios.ts
+++ b/tns-core-modules/application/application.ios.ts
@@ -161,7 +161,7 @@ class IOSApplication implements IOSApplicationDefinition {
             this.setWindowContent(args.root);
         } else {
             this._window = UIApplication.sharedApplication.delegate.window;
-        }
+        }   
     }
 
     @profile
@@ -373,10 +373,10 @@ function setViewControllerView(view: View): void {
     }
 }
 
-global.__onLiveSync = function () {
+global.__onLiveSync = function __onLiveSync(context?: HmrContext) {
     if (!started) {
         return;
     }
 
-    livesync();
-}
+    livesync(context);
+}
\ No newline at end of file
diff --git a/tns-core-modules/module.d.ts b/tns-core-modules/module.d.ts
index 5fd5d161d..0a0f6a033 100644
--- a/tns-core-modules/module.d.ts
+++ b/tns-core-modules/module.d.ts
@@ -51,7 +51,7 @@ declare namespace NodeJS {
         __native?: any;
         __inspector?: any;
         __extends: any;
-        __onLiveSync: () => void;
+        __onLiveSync: (context?: { type: string, module: string }) => void;
         __onLiveSyncCore: () => void;
         __onUncaughtError: (error: NativeScriptError) => void;
         TNS_WEBPACK?: boolean;
@@ -64,6 +64,27 @@ declare function clearTimeout(timeoutId: number): void;
 declare function setInterval(callback: (...args: any[]) => void, ms: number, ...args: any[]): number;
 declare function clearInterval(intervalId: number): void;
 
+declare enum HmrType {
+    markup = "markup",
+    script = "script",
+    style = "style"
+}
+
+/**
+ * Define a context for Hot Module Replacement.
+ */
+interface HmrContext {
+    /**
+     * The type of module for replacement.
+     */
+    type: HmrType;
+
+    /**
+     * The module for replacement.
+     */
+    module: string;
+}
+
 /**
  * An extended JavaScript Error which will have the nativeError property initialized in case the error is caused by executing platform-specific code.
  */
diff --git a/tns-core-modules/ui/frame/frame.android.ts b/tns-core-modules/ui/frame/frame.android.ts
index 1f56a8eb2..6756bf915 100644
--- a/tns-core-modules/ui/frame/frame.android.ts
+++ b/tns-core-modules/ui/frame/frame.android.ts
@@ -1198,4 +1198,4 @@ export function setActivityCallbacks(activity: android.support.v7.app.AppCompatA
 
 export function setFragmentCallbacks(fragment: android.support.v4.app.Fragment): void {
     fragment[CALLBACKS] = new FragmentCallbacksImplementation();
-}
+}
\ No newline at end of file
diff --git a/tns-core-modules/ui/page/page-common.ts b/tns-core-modules/ui/page/page-common.ts
index 0d85ab1ab..28814e186 100644
--- a/tns-core-modules/ui/page/page-common.ts
+++ b/tns-core-modules/ui/page/page-common.ts
@@ -17,17 +17,17 @@ export class PageBase extends ContentView implements PageDefinition {
     public static navigatedToEvent = "navigatedTo";
     public static navigatingFromEvent = "navigatingFrom";
     public static navigatedFromEvent = "navigatedFrom";
-  
+
     private _navigationContext: any;
     private _actionBar: ActionBar;
 
     public _frame: Frame;
-    
+
     public actionBarHidden: boolean;
     public enableSwipeBackNavigation: boolean;
     public backgroundSpanUnderStatusBar: boolean;
     public hasActionBar: boolean;
-    
+
     get navigationContext(): any {
         return this._navigationContext;
     }
@@ -89,7 +89,7 @@ export class PageBase extends ContentView implements PageDefinition {
         const frame = this.parent;
         return frame instanceof Frame ? frame : undefined;
     }
-    
+
     private createNavigatedData(eventName: string, isBackNavigation: boolean): NavigatedData {
         return {
             eventName: eventName,
@@ -103,6 +103,13 @@ export class PageBase extends ContentView implements PageDefinition {
     public onNavigatingTo(context: any, isBackNavigation: boolean, bindingContext?: any) {
         this._navigationContext = context;
 
+        if (isBackNavigation && this._styleScope) {
+            this._styleScope.ensureSelectors();
+            if (!this._cssState.isSelectorsLatestVersionApplied()) {
+                this._onCssStateChange();
+            }
+        }
+
         //https://github.com/NativeScript/NativeScript/issues/731
         if (!isBackNavigation && bindingContext !== undefined && bindingContext !== null) {
             this.bindingContext = bindingContext;
diff --git a/tns-core-modules/ui/styling/style-scope.d.ts b/tns-core-modules/ui/styling/style-scope.d.ts
index b404ce9a7..b5bf01684 100644
--- a/tns-core-modules/ui/styling/style-scope.d.ts
+++ b/tns-core-modules/ui/styling/style-scope.d.ts
@@ -19,6 +19,11 @@ export class CssState {
      * Gets the static selectors that match the view and the dynamic selectors that may potentially match the view.
      */
     public changeMap: ChangeMap<ViewBase>;
+
+    /**
+     * Checks whether style scope and CSS state selectors are in sync.
+     */
+    public isSelectorsLatestVersionApplied(): boolean
 }
 
 export class StyleScope {
@@ -29,6 +34,9 @@ export class StyleScope {
     public static createSelectorsFromImports(tree: SyntaxTree, keyframes: Object): RuleSet[];
     public ensureSelectors(): number;
 
+    public isApplicationCssSelectorsLatestVersionApplied(): boolean;
+    public isLocalCssSelectorsLatestVersionApplied(): boolean;
+
     public applySelectors(view: ViewBase): void
     public query(options: Node): SelectorCore[];
 
diff --git a/tns-core-modules/ui/styling/style-scope.ts b/tns-core-modules/ui/styling/style-scope.ts
index 8f3cf607c..a915b559d 100644
--- a/tns-core-modules/ui/styling/style-scope.ts
+++ b/tns-core-modules/ui/styling/style-scope.ts
@@ -271,7 +271,7 @@ export function removeTaggedAdditionalCSS(tag: String | Number): Boolean {
             changed = true;
         }
     }
-    if (changed) {  mergeCssSelectors(); }
+    if (changed) { mergeCssSelectors(); }
     return changed;
 }
 
@@ -343,6 +343,7 @@ export class CssState {
     _appliedChangeMap: Readonly<ChangeMap<ViewBase>>;
     _appliedPropertyValues: Readonly<{}>;
     _appliedAnimations: ReadonlyArray<kam.KeyframeAnimation>;
+    _appliedSelectorsVersion: number;
 
     _match: SelectorsMatch<ViewBase>;
     _matchInvalid: boolean;
@@ -367,6 +368,10 @@ export class CssState {
         }
     }
 
+    public isSelectorsLatestVersionApplied(): boolean {
+        return this.view._styleScope._getSelectorsVersion() === this._appliedSelectorsVersion;
+    }
+
     public onLoaded(): void {
         if (this._matchInvalid) {
             this.updateMatch();
@@ -381,7 +386,12 @@ export class CssState {
 
     @profile
     private updateMatch() {
-        this._match = this.view._styleScope ? this.view._styleScope.matchSelectors(this.view) : CssState.emptyMatch;
+        if (this.view._styleScope) {
+            this._appliedSelectorsVersion = this.view._styleScope._getSelectorsVersion();
+            this._match = this.view._styleScope.matchSelectors(this.view);
+        } else {
+            this._match = CssState.emptyMatch;
+        }
         this._matchInvalid = false;
     }
 
@@ -597,8 +607,8 @@ export class StyleScope {
     }
 
     public ensureSelectors(): number {
-        if (this._applicationCssSelectorsAppliedVersion !== applicationCssSelectorVersion ||
-            this._localCssSelectorVersion !== this._localCssSelectorsAppliedVersion ||
+        if (!this.isApplicationCssSelectorsLatestVersionApplied() ||
+            !this.isLocalCssSelectorsLatestVersionApplied() ||
             !this._mergedCssSelectors) {
 
             this._createSelectors();
@@ -607,6 +617,14 @@ export class StyleScope {
         return this._getSelectorsVersion();
     }
 
+    public isApplicationCssSelectorsLatestVersionApplied(): boolean {
+        return this._applicationCssSelectorsAppliedVersion === applicationCssSelectorVersion;
+    }
+
+    public isLocalCssSelectorsLatestVersionApplied(): boolean {
+        return this._localCssSelectorsAppliedVersion === this._localCssSelectorVersion;
+    }
+
     @profile
     private _createSelectors() {
         let toMerge: RuleSet[][] = [];