diff --git a/example/StackNavigator.tsx b/example/StackNavigator.tsx
index b725196a..06da173d 100644
--- a/example/StackNavigator.tsx
+++ b/example/StackNavigator.tsx
@@ -175,6 +175,7 @@ const StackRouter: Router<CommonAction | Action> = {
             ],
           };
         }
+
         return null;
 
       case 'REPLACE': {
@@ -192,6 +193,36 @@ const StackRouter: Router<CommonAction | Action> = {
         };
       }
 
+      case 'UPDATE': {
+        if (
+          action.payload.name !== undefined &&
+          !state.routeNames.includes(action.payload.name)
+        ) {
+          return null;
+        }
+
+        const index =
+          action.payload.key !== undefined
+            ? state.routes.findIndex(route => route.key === action.payload.key)
+            : state.index;
+
+        if (index === -1) {
+          return null;
+        }
+
+        return {
+          ...state,
+          routes: [
+            ...state.routes.slice(0, index),
+            {
+              ...state.routes[index],
+              ...action.payload,
+            },
+            ...state.routes.slice(index + 1),
+          ],
+        };
+      }
+
       case 'GO_BACK':
         return StackRouter.getStateForAction(state, {
           type: 'POP',
diff --git a/example/TabNavigator.tsx b/example/TabNavigator.tsx
index 6f899944..c8f95ae4 100644
--- a/example/TabNavigator.tsx
+++ b/example/TabNavigator.tsx
@@ -117,18 +117,33 @@ const TabRouter: Router<Action | CommonAction> = {
 
         return null;
 
-      case 'REPLACE': {
+      case 'UPDATE': {
+        if (
+          action.payload.name !== undefined &&
+          !state.routeNames.includes(action.payload.name)
+        ) {
+          return null;
+        }
+
+        const index =
+          action.payload.key !== undefined
+            ? state.routes.findIndex(route => route.key === action.payload.key)
+            : state.index;
+
+        if (index === -1) {
+          return null;
+        }
+
         return {
           ...state,
-          routes: state.routes.map((route, i) =>
-            i === state.index
-              ? {
-                  key: `${action.payload.name}-${shortid()}`,
-                  name: action.payload.name,
-                  params: action.payload.params,
-                }
-              : route
-          ),
+          routes: [
+            ...state.routes.slice(0, index),
+            {
+              ...state.routes[index],
+              ...action.payload,
+            },
+            ...state.routes.slice(index + 1),
+          ],
         };
       }
 
diff --git a/example/index.tsx b/example/index.tsx
index 66980eac..9bcd622f 100644
--- a/example/index.tsx
+++ b/example/index.tsx
@@ -150,7 +150,7 @@ function App() {
           name="first"
           component={First}
           options={{ title: 'Foo' }}
-          defaultParams={{ author: 'Jane' }}
+          initialParams={{ author: 'Jane' }}
         />
         <MyStack.Screen
           name="second"
diff --git a/src/BaseActions.tsx b/src/BaseActions.tsx
index 8a90bab7..b79f7e57 100644
--- a/src/BaseActions.tsx
+++ b/src/BaseActions.tsx
@@ -1,4 +1,4 @@
-import { PartialState } from './types';
+import { PartialState, Route } from './types';
 
 export type Action =
   | { type: 'GO_BACK' }
@@ -10,6 +10,7 @@ export type Action =
       type: 'REPLACE';
       payload: { name: string; params?: object };
     }
+  | { type: 'UPDATE'; payload: Partial<Route> }
   | {
       type: 'RESET';
       payload: PartialState & { key?: string };
@@ -27,6 +28,10 @@ export function replace(name: string, params?: object): Action {
   return { type: 'REPLACE', payload: { name, params } };
 }
 
+export function update(route: Partial<Route>): Action {
+  return { type: 'UPDATE', payload: route };
+}
+
 export function reset(state: PartialState & { key?: string }): Action {
   return { type: 'RESET', payload: state };
 }
diff --git a/src/__tests__/index.test.tsx b/src/__tests__/index.test.tsx
index 11eec4b1..d246fd44 100644
--- a/src/__tests__/index.test.tsx
+++ b/src/__tests__/index.test.tsx
@@ -115,7 +115,7 @@ it('initializes state for a navigator on navigation', () => {
         <Screen
           name="foo"
           component={FooScreen}
-          defaultParams={{ count: 10 }}
+          initialParams={{ count: 10 }}
         />
         <Screen name="bar" component={jest.fn()} />
         <Screen name="baz">
diff --git a/src/types.tsx b/src/types.tsx
index 975fe963..d346e39d 100644
--- a/src/types.tsx
+++ b/src/types.tsx
@@ -104,9 +104,17 @@ export type Router<Action extends NavigationAction = CommonAction> = {
     action: Action
   ): NavigationState | null;
 
+  /**
+   * Update state for a child navigator and focus it
+   *
+   * @param state State object to apply the action on.
+   * @param options.update Updated navigation state for the child navigator.
+   * @param options.focus Whether to focus the new child.
+   * @param options.key Route key of the child to update.
+   */
   getStateForChildUpdate(
     state: NavigationState,
-    payload: {
+    options: {
       update: NavigationState;
       focus: boolean;
       key: string | undefined;
@@ -116,21 +124,17 @@ export type Router<Action extends NavigationAction = CommonAction> = {
   /**
    * Whether the action bubbles to other navigators
    * When an action isn't handled by current navigator, it can be passed to nested navigators
+   *
+   * @param action Action object to check.
    */
-  shouldActionPropagateToChildren(
-    action: NavigationAction,
-    navigatorKey: string,
-    sourceNavigatorKey?: string
-  ): boolean;
+  shouldActionPropagateToChildren(action: NavigationAction): boolean;
 
   /**
    * Whether the action should also change focus in parent navigator
+   *
+   * @param action Action object to check.
    */
-  shouldActionChangeFocus(
-    action: NavigationAction,
-    navigatorKey: string,
-    sourceNavigatorKey?: string
-  ): boolean;
+  shouldActionChangeFocus(action: NavigationAction): boolean;
 
   /**
    * Action creators for the router.
@@ -186,6 +190,17 @@ export type NavigationHelpers<
       : [RouteName, ParamList[RouteName]]
   ): void;
 
+  /**
+   * Update properties for a route, for example: updating params.
+   * If a key is provided, the route with matching key will be updated.
+   * If no key is provided, the focused route will be updated.
+   *
+   * @param route New properties for the route object.
+   */
+  update<RouteName extends keyof ParamList>(
+    route: Partial<RouteProp<ParamList, RouteName>>
+  ): void;
+
   /**
    * Reset the navigation state to the provided state.
    * If a key is provided, the state with matching key will be reset.
@@ -258,9 +273,9 @@ export type RouteConfig<
   options?: Options;
 
   /**
-   * Default params object for the route.
+   * Initial params object for the route.
    */
-  defaultParams?: ParamList[RouteName];
+  initialParams?: ParamList[RouteName];
 } & (
   | {
       /**
diff --git a/src/useNavigationBuilder.tsx b/src/useNavigationBuilder.tsx
index d0127d55..1e8db95d 100644
--- a/src/useNavigationBuilder.tsx
+++ b/src/useNavigationBuilder.tsx
@@ -55,7 +55,7 @@ export default function useNavigationBuilder(
       : routeNames[0];
   const initialParamsList = routeNames.reduce(
     (acc, curr) => {
-      acc[curr] = screens[curr].defaultParams;
+      acc[curr] = screens[curr].initialParams;
       return acc;
     },
     {} as { [key: string]: object | undefined }
diff --git a/src/useOnAction.tsx b/src/useOnAction.tsx
index c5ee8099..8470fa6f 100644
--- a/src/useOnAction.tsx
+++ b/src/useOnAction.tsx
@@ -41,11 +41,7 @@ export default function useOnAction({
 
       if (result !== null) {
         if (handleChildUpdateParent) {
-          const shouldFocus = router.shouldActionChangeFocus(
-            action,
-            state.key,
-            sourceNavigatorKey
-          );
+          const shouldFocus = router.shouldActionChangeFocus(action);
 
           handleChildUpdateParent(result, shouldFocus, key);
         } else if (state !== result) {
@@ -62,13 +58,7 @@ export default function useOnAction({
         }
       }
 
-      if (
-        router.shouldActionPropagateToChildren(
-          action,
-          state.key,
-          sourceNavigatorKey
-        )
-      ) {
+      if (router.shouldActionPropagateToChildren(action)) {
         for (let i = actionListeners.length - 1; i >= 0; i--) {
           const listener = actionListeners[i];