diff --git a/Libraries/Components/View/ReactNativeStyleAttributes.js b/Libraries/Components/View/ReactNativeStyleAttributes.js
index 93ea3a35b..46c821f66 100644
--- a/Libraries/Components/View/ReactNativeStyleAttributes.js
+++ b/Libraries/Components/View/ReactNativeStyleAttributes.js
@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @format
+ * @format strict-local
  * @flow
  */
 
@@ -14,19 +14,19 @@ const ImageStylePropTypes = require('ImageStylePropTypes');
 const TextStylePropTypes = require('TextStylePropTypes');
 const ViewStylePropTypes = require('ViewStylePropTypes');
 
-/* $FlowFixMe(>=0.54.0 site=react_native_oss) This comment suppresses an error
- * found when Flow v0.54 was deployed. To see the error delete this comment and
- * run Flow. */
-const keyMirror = require('fbjs/lib/keyMirror');
 const processColor = require('processColor');
 const processTransform = require('processTransform');
 const sizesDiffer = require('sizesDiffer');
 
-const ReactNativeStyleAttributes = {
-  ...keyMirror(ViewStylePropTypes),
-  ...keyMirror(TextStylePropTypes),
-  ...keyMirror(ImageStylePropTypes),
-};
+const ReactNativeStyleAttributes = {};
+
+for (const attributeName of Object.keys({
+  ...ViewStylePropTypes,
+  ...TextStylePropTypes,
+  ...ImageStylePropTypes,
+})) {
+  ReactNativeStyleAttributes[attributeName] = true;
+}
 
 ReactNativeStyleAttributes.transform = {process: processTransform};
 ReactNativeStyleAttributes.shadowOffset = {diff: sizesDiffer};
diff --git a/Libraries/Components/View/ReactNativeViewAttributes.js b/Libraries/Components/View/ReactNativeViewAttributes.js
index c1639e136..5b4ab1c6c 100644
--- a/Libraries/Components/View/ReactNativeViewAttributes.js
+++ b/Libraries/Components/View/ReactNativeViewAttributes.js
@@ -4,8 +4,8 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
+ * @flow strict-local
  * @format
- * @flow strict
  */
 
 'use strict';
diff --git a/Libraries/Renderer/shims/ReactNativeTypes.js b/Libraries/Renderer/shims/ReactNativeTypes.js
index 8daf4fe7f..f9058abc1 100644
--- a/Libraries/Renderer/shims/ReactNativeTypes.js
+++ b/Libraries/Renderer/shims/ReactNativeTypes.js
@@ -36,8 +36,8 @@ export type MeasureLayoutOnSuccessCallback = (
 type AttributeType =
   | true
   | $ReadOnly<{|
-      diff: ?<T>(arg1: T, arg2: T) => boolean,
-      process: ?(arg1: any) => any,
+      diff?: <T>(arg1: T, arg2: T) => boolean,
+      process?: (arg1: any) => any,
     |}>;
 
 export type AttributeConfiguration<