diff --git a/workbench/inputs/Libraries/Utilities/differ/sizesDiffer.js.flow b/workbench/inputs/Libraries/Utilities/differ/sizesDiffer.js.flow
new file mode 100644
index 00000000..e5c61883
--- /dev/null
+++ b/workbench/inputs/Libraries/Utilities/differ/sizesDiffer.js.flow
@@ -0,0 +1,11 @@
+// @flow
+// TODO: Move these Flow typings upstream
+type Size = {
+  width: ?number,
+  height: ?number,
+  ...
+}
+
+declare var sizesDiffer: (one: ?Size, two: ?Size) => boolean
+
+declare module.exports: typeof sizesDiffer
diff --git a/workbench/outputs/android/Libraries/Utilities/differ/sizesDiffer.d.ts b/workbench/outputs/android/Libraries/Utilities/differ/sizesDiffer.d.ts
new file mode 100644
index 00000000..495c35b5
--- /dev/null
+++ b/workbench/outputs/android/Libraries/Utilities/differ/sizesDiffer.d.ts
@@ -0,0 +1,10 @@
+import { $TypeOf } from "flow2dts-flow-types-polyfill";
+// @flow
+// TODO: Move these Flow typings upstream
+declare type Size = {
+  width: null | undefined | number;
+  height: null | undefined | number;
+};
+declare var sizesDiffer: (one: null | undefined | Size, two: null | undefined | Size) => boolean;
+declare const $f2tExportDefault: $TypeOf<typeof sizesDiffer>;
+export default $f2tExportDefault;
\ No newline at end of file
diff --git a/workbench/outputs/ios/Libraries/Utilities/differ/sizesDiffer.d.ts b/workbench/outputs/ios/Libraries/Utilities/differ/sizesDiffer.d.ts
new file mode 100644
index 00000000..495c35b5
--- /dev/null
+++ b/workbench/outputs/ios/Libraries/Utilities/differ/sizesDiffer.d.ts
@@ -0,0 +1,10 @@
+import { $TypeOf } from "flow2dts-flow-types-polyfill";
+// @flow
+// TODO: Move these Flow typings upstream
+declare type Size = {
+  width: null | undefined | number;
+  height: null | undefined | number;
+};
+declare var sizesDiffer: (one: null | undefined | Size, two: null | undefined | Size) => boolean;
+declare const $f2tExportDefault: $TypeOf<typeof sizesDiffer>;
+export default $f2tExportDefault;
\ No newline at end of file