diff --git a/packages/react-navigation/src/routers/StackRouter.js b/packages/react-navigation/src/routers/StackRouter.js
index 7f035d3a..fb802c53 100644
--- a/packages/react-navigation/src/routers/StackRouter.js
+++ b/packages/react-navigation/src/routers/StackRouter.js
@@ -206,7 +206,7 @@ export default (routeConfigs, stackConfig = {}) => {
           }
         });
 
-        if (lastRouteIndex !== -1) {
+        if (action.type !== NavigationActions.PUSH && lastRouteIndex !== -1) {
           // If index is unchanged and params are not being set, leave state identity intact
           if (state.index === lastRouteIndex && !action.params) {
             return state;
diff --git a/packages/react-navigation/src/routers/__tests__/StackRouter-test.js b/packages/react-navigation/src/routers/__tests__/StackRouter-test.js
index bae0fba2..31606bbf 100644
--- a/packages/react-navigation/src/routers/__tests__/StackRouter-test.js
+++ b/packages/react-navigation/src/routers/__tests__/StackRouter-test.js
@@ -684,6 +684,26 @@ describe('StackRouter', () => {
     }).toThrow();
   });
 
+  test('Push adds new routes every time', () => {
+    const TestRouter = StackRouter({
+      foo: { screen: () => <div /> },
+      bar: { screen: () => <div /> },
+    });
+    const initState = TestRouter.getStateForAction(NavigationActions.init());
+    const pushedState = TestRouter.getStateForAction(
+      NavigationActions.push({ routeName: 'bar' }),
+      initState
+    );
+    expect(pushedState.index).toEqual(1);
+    expect(pushedState.routes[1].routeName).toEqual('bar');
+    const secondPushedState = TestRouter.getStateForAction(
+      NavigationActions.push({ routeName: 'bar' }),
+      pushedState
+    );
+    expect(secondPushedState.index).toEqual(2);
+    expect(secondPushedState.routes[2].routeName).toEqual('bar');
+  });
+
   test('Navigate backwards with key removes leading routes', () => {
     const TestRouter = StackRouter({
       foo: { screen: () => <div /> },