diff --git a/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js b/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js
index 31dcf36dc93..9023c5f4811 100644
--- a/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js
+++ b/Libraries/Components/DrawerAndroid/DrawerLayoutAndroid.android.js
@@ -28,7 +28,7 @@ const DRAWER_STATES = ['Idle', 'Dragging', 'Settling'];
 
 import type {ViewStyleProp} from '../../StyleSheet/StyleSheet';
 import type {ColorValue} from '../../StyleSheet/StyleSheetTypes';
-import type {SyntheticEvent} from '../../Types/CoreEventTypes';
+import type {DirectEventHandler} from '../../Types/CodegenTypes';
 import type {
   MeasureOnSuccessCallback,
   MeasureInWindowOnSuccessCallback,
@@ -37,17 +37,9 @@ import type {
 
 type DrawerStates = 'Idle' | 'Dragging' | 'Settling';
 
-type DrawerStateEvent = SyntheticEvent<
-  $ReadOnly<{|
-    drawerState: number,
-  |}>,
->;
-
-type DrawerSlideEvent = SyntheticEvent<
-  $ReadOnly<{|
-    offset: number,
-  |}>,
->;
+type DrawerSlideEvent = $ReadOnly<{|
+  offset: number,
+|}>;
 
 type Props = $ReadOnly<{|
   /**
@@ -93,7 +85,7 @@ type Props = $ReadOnly<{|
   /**
    * Function called whenever there is an interaction with the navigation view.
    */
-  onDrawerSlide?: ?(event: DrawerSlideEvent) => mixed,
+  onDrawerSlide?: ?DirectEventHandler<DrawerSlideEvent>,
 
   /**
    * Function called when the drawer state has changed. The drawer can be in 3 states:
@@ -176,7 +168,13 @@ class DrawerLayoutAndroid extends React.Component<Props, State> {
   state = {statusBarBackgroundColor: null};
 
   render() {
-    const {onDrawerStateChanged, renderNavigationView, ...props} = this.props;
+    const {
+      onDrawerStateChanged,
+      renderNavigationView,
+      onDrawerOpen,
+      onDrawerClose,
+      ...props
+    } = this.props;
     const drawStatusBar =
       Platform.Version >= 21 && this.props.statusBarBackgroundColor;
     const drawerViewWrapper = (
@@ -233,7 +231,7 @@ class DrawerLayoutAndroid extends React.Component<Props, State> {
     );
   }
 
-  _onDrawerSlide = (event: DrawerSlideEvent) => {
+  _onDrawerSlide = event => {
     if (this.props.onDrawerSlide) {
       this.props.onDrawerSlide(event);
     }
@@ -254,7 +252,7 @@ class DrawerLayoutAndroid extends React.Component<Props, State> {
     }
   };
 
-  _onDrawerStateChanged = (event: DrawerStateEvent) => {
+  _onDrawerStateChanged = event => {
     if (this.props.onDrawerStateChanged) {
       this.props.onDrawerStateChanged(
         DRAWER_STATES[event.nativeEvent.drawerState],
diff --git a/Libraries/Components/RefreshControl/RefreshControl.js b/Libraries/Components/RefreshControl/RefreshControl.js
index c0eea823b81..773d73d2490 100644
--- a/Libraries/Components/RefreshControl/RefreshControl.js
+++ b/Libraries/Components/RefreshControl/RefreshControl.js
@@ -81,7 +81,7 @@ export type RefreshControlProps = $ReadOnly<{|
   /**
    * Called when the view starts refreshing.
    */
-  onRefresh?: ?() => mixed,
+  onRefresh?: ?() => void,
 
   /**
    * Whether the view should be indicating an active refresh.
diff --git a/Libraries/Components/SegmentedControlIOS/SegmentedControlIOS.ios.js b/Libraries/Components/SegmentedControlIOS/SegmentedControlIOS.ios.js
index a98e26e909b..f438b1b8573 100644
--- a/Libraries/Components/SegmentedControlIOS/SegmentedControlIOS.ios.js
+++ b/Libraries/Components/SegmentedControlIOS/SegmentedControlIOS.ios.js
@@ -43,7 +43,7 @@ type SegmentedControlIOSProps = $ReadOnly<{|
   /**
    * Callback that is called when the user taps a segment
    */
-  onChange?: ?(event: SyntheticEvent<OnChangeEvent>) => mixed,
+  onChange?: ?(event: SyntheticEvent<OnChangeEvent>) => void,
   /**
    * Callback that is called when the user taps a segment;
    * passes the segment's value as an argument
diff --git a/Libraries/Modal/Modal.js b/Libraries/Modal/Modal.js
index fad0538e45c..38e77f34f83 100644
--- a/Libraries/Modal/Modal.js
+++ b/Libraries/Modal/Modal.js
@@ -29,7 +29,7 @@ const ModalEventEmitter =
 import type EmitterSubscription from '../vendor/emitter/EmitterSubscription';
 import type {ViewProps} from '../Components/View/ViewPropTypes';
 import type {SyntheticEvent} from '../Types/CoreEventTypes';
-
+import type {DirectEventHandler} from '../Types/CodegenTypes';
 /**
  * The Modal component is a simple way to present content above an enclosing view.
  *
@@ -42,11 +42,9 @@ import type {SyntheticEvent} from '../Types/CoreEventTypes';
 // destroyed before the callback is fired.
 let uniqueModalIdentifier = 0;
 
-export type OrientationChangeEvent = SyntheticEvent<
-  $ReadOnly<{|
-    orientation: 'portrait' | 'landscape',
-  |}>,
->;
+type OrientationChangeEvent = $ReadOnly<{|
+  orientation: 'portrait' | 'landscape',
+|}>;
 
 export type Props = $ReadOnly<{|
   ...ViewProps,
@@ -101,7 +99,7 @@ export type Props = $ReadOnly<{|
    *
    * See https://facebook.github.io/react-native/docs/modal.html#onrequestclose
    */
-  onRequestClose?: ?(event?: SyntheticEvent<null>) => mixed,
+  onRequestClose?: ?DirectEventHandler<null>,
 
   /**
    * The `onShow` prop allows passing a function that will be called once the
@@ -109,7 +107,7 @@ export type Props = $ReadOnly<{|
    *
    * See https://facebook.github.io/react-native/docs/modal.html#onshow
    */
-  onShow?: ?(event?: SyntheticEvent<null>) => mixed,
+  onShow?: ?DirectEventHandler<null>,
 
   /**
    * The `onDismiss` prop allows passing a function that will be called once
@@ -142,7 +140,7 @@ export type Props = $ReadOnly<{|
    *
    * See https://facebook.github.io/react-native/docs/modal.html#onorientationchange
    */
-  onOrientationChange?: ?(event: OrientationChangeEvent) => mixed,
+  onOrientationChange?: ?DirectEventHandler<OrientationChangeEvent>,
 |}>;
 
 class Modal extends React.Component<Props> {
diff --git a/Libraries/Types/CodegenTypes.js b/Libraries/Types/CodegenTypes.js
index 0ef355ddbd6..2b41832a61a 100644
--- a/Libraries/Types/CodegenTypes.js
+++ b/Libraries/Types/CodegenTypes.js
@@ -18,11 +18,11 @@ import type {SyntheticEvent} from './CoreEventTypes';
 export type BubblingEventHandler<
   T,
   PaperName: string | empty = empty, // eslint-disable-line no-unused-vars
-> = (event: SyntheticEvent<T>) => mixed;
+> = (event: SyntheticEvent<T>) => void | Promise<void>;
 export type DirectEventHandler<
   T,
   PaperName: string | empty = empty, // eslint-disable-line no-unused-vars
-> = (event: SyntheticEvent<T>) => mixed;
+> = (event: SyntheticEvent<T>) => void | Promise<void>;
 
 // Prop types
 export type Float = number;