diff --git a/Libraries/Components/Picker/Picker.js b/Libraries/Components/Picker/Picker.js
index 88a70a59f6d05f..c96f18baf6fbad 100644
--- a/Libraries/Components/Picker/Picker.js
+++ b/Libraries/Components/Picker/Picker.js
@@ -32,7 +32,7 @@ type PickerItemProps = $ReadOnly<{|
    * The value to be passed to picker's `onValueChange` callback when
    * this item is selected. Can be a string or an integer.
    */
-  value?: any,
+  value?: ?(number | string),
 
   /**
    * Color of this item's text.
@@ -63,14 +63,14 @@ type PickerProps = $ReadOnly<{|
   /**
    * Value matching value of one of the items. Can be a string or an integer.
    */
-  selectedValue?: any,
+  selectedValue?: ?(number | string),
 
   /**
    * Callback for when an item is selected. This is called with the following parameters:
    *   - `itemValue`: the `value` prop of the item that was selected
-   *   - `itemPosition`: the index of the selected item in this picker
+   *   - `itemIndex`: the index of the selected item in this picker
    */
-  onValueChange?: ?(newValue: any, newIndex: number) => mixed,
+  onValueChange?: ?(itemValue: string | number, itemIndex: number) => mixed,
 
   /**
    * If set to false, the picker will be disabled, i.e. the user will not be able to make a
diff --git a/Libraries/Components/Picker/PickerAndroid.android.js b/Libraries/Components/Picker/PickerAndroid.android.js
index 2fb010506853e0..2c1ae760e27775 100644
--- a/Libraries/Components/Picker/PickerAndroid.android.js
+++ b/Libraries/Components/Picker/PickerAndroid.android.js
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  *
  * @format
- * @flow
+ * @flow strict-local
  */
 
 'use strict';
@@ -34,18 +34,34 @@ type PickerAndroidChangeEvent = SyntheticEvent<
 type PickerAndroidProps = $ReadOnly<{|
   children?: React.Node,
   style?: ?TextStyleProp,
-  selectedValue?: any,
+  selectedValue?: ?(number | string),
   enabled?: ?boolean,
   mode?: ?('dialog' | 'dropdown'),
-  onValueChange?: ?(newValue: any, newIndex: number) => mixed,
+  onValueChange?: ?(itemValue: ?(string | number), itemIndex: number) => mixed,
   prompt?: ?string,
   testID?: string,
 |}>;
 
+type Item = $ReadOnly<{|
+  label: string,
+  value: ?(number | string),
+  color?: ?number,
+|}>;
+
+type PickerAndroidState = {|
+  initialSelectedIndex: number,
+  selectedIndex: number,
+  items: $ReadOnlyArray<Item>,
+|};
+
 /**
  * Not exposed as a public API - use <Picker> instead.
  */
-class PickerAndroid extends React.Component<PickerAndroidProps, *> {
+
+class PickerAndroid extends React.Component<
+  PickerAndroidProps,
+  PickerAndroidState,
+> {
   /* $FlowFixMe(>=0.78.0 site=react_native_android_fb) This issue was found
    * when making Flow check .android.js files. */
   constructor(props, context) {
diff --git a/Libraries/Components/Picker/PickerIOS.ios.js b/Libraries/Components/Picker/PickerIOS.ios.js
index fa2fabc09404e2..594f913599bff6 100644
--- a/Libraries/Components/Picker/PickerIOS.ios.js
+++ b/Libraries/Components/Picker/PickerIOS.ios.js
@@ -27,14 +27,14 @@ import type {TextStyleProp} from 'StyleSheet';
 
 type PickerIOSChangeEvent = SyntheticEvent<
   $ReadOnly<{|
-    newValue: any,
+    newValue: number | string,
     newIndex: number,
   |}>,
 >;
 
 type RCTPickerIOSItemType = $ReadOnly<{|
   label: ?Label,
-  value: ?any,
+  value: ?(number | string),
   textColor: ?number,
 |}>;
 
@@ -62,8 +62,8 @@ type Props = $ReadOnly<{|
   children: React.ChildrenArray<React.Element<typeof PickerIOSItem>>,
   itemStyle?: ?TextStyleProp,
   onChange?: ?(event: PickerIOSChangeEvent) => mixed,
-  onValueChange?: ?(newValue: any, newIndex: number) => mixed,
-  selectedValue: any,
+  onValueChange?: ?(itemValue: string | number, itemIndex: number) => mixed,
+  selectedValue: ?(number | string),
 |}>;
 
 type State = {|
@@ -73,7 +73,7 @@ type State = {|
 
 type ItemProps = $ReadOnly<{|
   label: ?Label,
-  value?: ?any,
+  value?: ?(number | string),
   color?: ?ColorValue,
 |}>;
 
diff --git a/Libraries/Utilities/__tests__/deepFreezeAndThrowOnMutationInDev-test.js b/Libraries/Utilities/__tests__/deepFreezeAndThrowOnMutationInDev-test.js
index 1ed6231c663603..f3f8c016026e32 100644
--- a/Libraries/Utilities/__tests__/deepFreezeAndThrowOnMutationInDev-test.js
+++ b/Libraries/Utilities/__tests__/deepFreezeAndThrowOnMutationInDev-test.js
@@ -134,7 +134,7 @@ describe('deepFreezeAndThrowOnMutationInDev', function() {
     expect(o.key1.key2).toBe('newValue');
   });
 
-  it('shouldn\'t recurse infinitely', () => {
+  it("shouldn't recurse infinitely", () => {
     __DEV__ = true;
     const o = {};
     o.circular = o;
diff --git a/RNTester/js/PermissionsExampleAndroid.android.js b/RNTester/js/PermissionsExampleAndroid.android.js
index 285b2827f31fdd..e470d755f51b87 100644
--- a/RNTester/js/PermissionsExampleAndroid.android.js
+++ b/RNTester/js/PermissionsExampleAndroid.android.js
@@ -76,7 +76,7 @@ class PermissionsExample extends React.Component<{}, $FlowFixMeState> {
     );
   }
 
-  _onSelectPermission = (permission: string) => {
+  _onSelectPermission = (permission: string | number) => {
     this.setState({
       permission: permission,
     });
diff --git a/RNTester/js/PickerExample.js b/RNTester/js/PickerExample.js
index ad234e5ebe8bad..4957916a4a8f26 100644
--- a/RNTester/js/PickerExample.js
+++ b/RNTester/js/PickerExample.js
@@ -116,7 +116,7 @@ class PickerExample extends React.Component<{}, $FlowFixMeState> {
     this.setState({mode: newMode});
   };
 
-  onValueChange = (key: string, value: string) => {
+  onValueChange = (key: string, value: string | number) => {
     const newState = {};
     newState[key] = value;
     this.setState(newState);