diff --git a/Libraries/Lists/SectionList.js b/Libraries/Lists/SectionList.js
index 87be13251..4d2120e78 100644
--- a/Libraries/Lists/SectionList.js
+++ b/Libraries/Lists/SectionList.js
@@ -129,7 +129,8 @@ type OptionalProps<SectionT: SectionBase<any>> = {
   /**
    * Used to extract a unique key for a given item at the specified index. Key is used for caching
    * and as the react key to track item re-ordering. The default extractor checks item.key, then
-   * falls back to using the index, like react does.
+   * falls back to using the index, like react does. Note that this sets keys for each item, but 
+   * each overall section still needs its own key.
    */
   keyExtractor: (item: Item, index: number) => string,
   /**