1 files changed, 2 insertions, 2 deletions
diff --git a/u/fn/either.ts b/u/fn/either.ts
index eaf77fd..12240d0 100644
--- a/u/fn/either.ts
+++ b/u/fn/either.ts
@@ -1,4 +1,4 @@
-import type { Mapper, Supplier } from "./mod.ts";
+import type { Mapper, Supplier } from "@emprespresso/pengueno";
 
 export interface IEither<E, T> {
   mapBoth: <Ee, Tt>(
@@ -21,7 +21,7 @@ export class Either<E, T> implements IEither<E, T> {
     return Either.right(okBranch(this.ok!));
   }
 
-  public flatMap<Tt>(mapper: Mapper<T, Either<E, Tt>>) {
+  public flatMap<Tt>(mapper: Mapper<T, Either<E, Tt>>): Either<E, Tt> {
     if (this.ok) return mapper(this.ok);
     return Either.left<E, Tt>(this.err!);
   }