1 files changed, 3 insertions, 3 deletions
diff --git a/u/types/fn/either.ts b/u/types/fn/either.ts
index 5e2dca0..0f65859 100644
--- a/u/types/fn/either.ts
+++ b/u/types/fn/either.ts
@@ -28,8 +28,8 @@ export interface IEither<E, T> extends Tagged<IEitherTag> {
     readonly fold: <_T>(leftFolder: Mapper<E, _T>, rightFolder: Mapper<T, _T>) => _T;
     readonly joinRight: <O, _T>(other: IEither<E, O>, mapper: (a: O, b: T) => _T) => IEither<E, _T>;
     readonly joinRightAsync: <O, _T>(
-        other: Supplier<Promise<IEither<E, O>>> | Promise<IEither<E, O>>,
-        mapper: BiMapper<O, T, _T>,
+        other: (() => Promise<IEither<E, O>>) | Promise<IEither<E, O>>,
+        mapper: (a: O, b: T) => _T,
     ) => Promise<IEither<E, _T>>;
 }
 
@@ -115,7 +115,7 @@ export class Either<E, T> extends _Tagged implements IEither<E, T> {
     ) {
         return this.flatMapAsync(async (t) => {
             const o = typeof other === 'function' ? other() : other;
-            return o.then((other) => other.mapRight((o) => mapper(o, t)));
+            return await o.then((other) => other.mapRight((o) => mapper(o, t)));
         });
     }