diff --git a/native/components/node-height-measurer.react.js b/native/components/node-height-measurer.react.js
--- a/native/components/node-height-measurer.react.js
+++ b/native/components/node-height-measurer.react.js
@@ -34,7 +34,7 @@
   +itemToMeasureKey: Item => ?string,
   // The "dummy" is the component whose height we will be measuring
   // We will only call this with items for which itemToMeasureKey returns truthy
-  +itemToDummy: Item => React.Element<mixed>,
+  +itemToDummy: Item => React.MixedElement,
   // Once we have the height, we need to merge it into the item
   +mergeItemWithHeight: (item: Item, height: ?number) => MergedItem,
   // We'll pass our results here when we're done