diff --git a/js/noms/src/list.js b/js/noms/src/list.js
index b3daeed02a..59af01deef 100644
--- a/js/noms/src/list.js
+++ b/js/noms/src/list.js
@@ -105,7 +105,7 @@ export default class List<T: Value> extends Collection<IndexedSequence<any>> {
    * function returns a promise `forEach` will continue but it will not return until all of those
    * promises have been fulfilled.
    */
-  async forEach(cb: (v: T, i: number) => ?Promise<void>): Promise<void> {
+  async forEach(cb: (v: T, i: number) => ?Promise<any>): Promise<void> {
     const cursor = await this.sequence.newCursorAt(0);
     const promises = [];
     return cursor.iter((v, i) => {
diff --git a/js/noms/src/map.js b/js/noms/src/map.js
index d9f334fea0..cbe08ad4ba 100644
--- a/js/noms/src/map.js
+++ b/js/noms/src/map.js
@@ -122,7 +122,7 @@ export default class Map<K: Value, V: Value> extends
     return equals(entry[KEY], key) ? entry[VALUE] : undefined;
   }
 
-  async forEach(cb: (v: V, k: K) => ?Promise<void>): Promise<void> {
+  async forEach(cb: (v: V, k: K) => ?Promise<any>): Promise<void> {
     const cursor = await this.sequence.newCursorAt(null);
     const promises = [];
     return cursor.iter(entry => {
diff --git a/js/noms/src/set.js b/js/noms/src/set.js
index 3835668d32..fbfb134323 100644
--- a/js/noms/src/set.js
+++ b/js/noms/src/set.js
@@ -77,7 +77,7 @@ export default class Set<T: Value> extends Collection<OrderedSequence<any, any>>
     return this._firstOrLast(true);
   }
 
-  async forEach(cb: (v: T) => ?Promise<void>): Promise<void> {
+  async forEach(cb: (v: T) => ?Promise<any>): Promise<void> {
     const cursor = await this.sequence.newCursorAt(null);
     const promises = [];
     return cursor.iter(v => {