diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9071db5c8..e2b0138a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,11 @@
 **Note**: A feature tagged as Experimental is in a
 high state of flux, you're at risk of it changing without notice.
 
+# 2.9.4
+
+- **Bug Fix**
+  - fix `filter` overloads in `NonEmptyArray` / `ReadonlyNonEmptyArray`, closes #1388 (@gcanti)
+
 # 2.9.3
 
 - **Polish**
diff --git a/docs/modules/NonEmptyArray.ts.md b/docs/modules/NonEmptyArray.ts.md
index a91195ac9..afb2ef526 100644
--- a/docs/modules/NonEmptyArray.ts.md
+++ b/docs/modules/NonEmptyArray.ts.md
@@ -353,7 +353,7 @@ Added in v2.0.0
 ```ts
 export declare function filter<A, B extends A>(
   refinement: Refinement<A, B>
-): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<A>>
+): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<B>>
 export declare function filter<A>(predicate: Predicate<A>): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<A>>
 ```
 
diff --git a/docs/modules/ReadonlyNonEmptyArray.ts.md b/docs/modules/ReadonlyNonEmptyArray.ts.md
index d1a75edb1..39cdf26c0 100644
--- a/docs/modules/ReadonlyNonEmptyArray.ts.md
+++ b/docs/modules/ReadonlyNonEmptyArray.ts.md
@@ -913,7 +913,7 @@ Added in v2.6.3
 ```ts
 export declare function filter<A, B extends A>(
   refinement: Refinement<A, B>
-): (nea: ReadonlyNonEmptyArray<A>) => Option<ReadonlyNonEmptyArray<A>>
+): (nea: ReadonlyNonEmptyArray<A>) => Option<ReadonlyNonEmptyArray<B>>
 export declare function filter<A>(
   predicate: Predicate<A>
 ): (nea: ReadonlyNonEmptyArray<A>) => Option<ReadonlyNonEmptyArray<A>>
diff --git a/dtslint/ts3.5/NonEmptyArray.ts b/dtslint/ts3.5/NonEmptyArray.ts
index 59c95c054..8afd17eac 100644
--- a/dtslint/ts3.5/NonEmptyArray.ts
+++ b/dtslint/ts3.5/NonEmptyArray.ts
@@ -2,7 +2,6 @@ import * as _ from '../../src/NonEmptyArray'
 import { Ord } from '../../src/Ord'
 import { pipe } from '../../src/function'
 
-declare const as: Array<string>
 declare const neas: _.NonEmptyArray<string>
 declare const nens: _.NonEmptyArray<number>
 declare const netns: _.NonEmptyArray<[number, string]>
@@ -89,3 +88,20 @@ pipe(
   _.bind('a', () => _.of(1)),
   _.bind('b', () => _.of('b'))
 )
+
+//
+// filter
+//
+
+declare const isNumber1: (sn: string | number) => sn is number
+declare const isNumber2: (sn: unknown) => sn is number
+declare const neasn: _.NonEmptyArray<string | number>
+
+// $ExpectType Option<NonEmptyArray<number>>
+pipe(neasn, _.filter(isNumber1))
+// $ExpectType Option<NonEmptyArray<number>>
+_.filter(isNumber1)(neasn)
+// $ExpectType Option<NonEmptyArray<number>>
+pipe(neasn, _.filter(isNumber2))
+// $ExpectType Option<NonEmptyArray<number>>
+_.filter(isNumber2)(neasn)
diff --git a/dtslint/ts3.5/ReadonlyNonEmptyArray.ts b/dtslint/ts3.5/ReadonlyNonEmptyArray.ts
index 42ab1843a..f0057b2da 100644
--- a/dtslint/ts3.5/ReadonlyNonEmptyArray.ts
+++ b/dtslint/ts3.5/ReadonlyNonEmptyArray.ts
@@ -89,3 +89,20 @@ pipe(
   _.bind('a', () => _.of(1)),
   _.bind('b', () => _.of('b'))
 )
+
+//
+// filter
+//
+
+declare const isNumber1: (sn: string | number) => sn is number
+declare const isNumber2: (sn: unknown) => sn is number
+declare const neasn: _.ReadonlyNonEmptyArray<string | number>
+
+// $ExpectType Option<ReadonlyNonEmptyArray<number>>
+pipe(neasn, _.filter(isNumber1))
+// $ExpectType Option<ReadonlyNonEmptyArray<number>>
+_.filter(isNumber1)(neasn)
+// $ExpectType Option<ReadonlyNonEmptyArray<number>>
+pipe(neasn, _.filter(isNumber2))
+// $ExpectType Option<ReadonlyNonEmptyArray<number>>
+_.filter(isNumber2)(neasn)
diff --git a/package.json b/package.json
index 8cc7bf7ef..8c55e8453 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "fp-ts",
-  "version": "2.9.3",
+  "version": "2.9.4",
   "description": "Functional programming in TypeScript",
   "main": "lib/index.js",
   "module": "es6/index.js",
diff --git a/src/NonEmptyArray.ts b/src/NonEmptyArray.ts
index 1f550158a..5f3973011 100644
--- a/src/NonEmptyArray.ts
+++ b/src/NonEmptyArray.ts
@@ -283,7 +283,7 @@ export function copy<A>(nea: NonEmptyArray<A>): NonEmptyArray<A> {
  */
 export function filter<A, B extends A>(
   refinement: Refinement<A, B>
-): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<A>>
+): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<B>>
 export function filter<A>(predicate: Predicate<A>): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<A>>
 export function filter<A>(predicate: Predicate<A>): (nea: NonEmptyArray<A>) => Option<NonEmptyArray<A>> {
   return RNEA.filter(predicate) as any
diff --git a/src/ReadonlyNonEmptyArray.ts b/src/ReadonlyNonEmptyArray.ts
index 46e041d34..d795e0ab1 100644
--- a/src/ReadonlyNonEmptyArray.ts
+++ b/src/ReadonlyNonEmptyArray.ts
@@ -343,7 +343,7 @@ export function modifyAt<A>(
  */
 export function filter<A, B extends A>(
   refinement: Refinement<A, B>
-): (nea: ReadonlyNonEmptyArray<A>) => Option<ReadonlyNonEmptyArray<A>>
+): (nea: ReadonlyNonEmptyArray<A>) => Option<ReadonlyNonEmptyArray<B>>
 export function filter<A>(predicate: Predicate<A>): (nea: ReadonlyNonEmptyArray<A>) => Option<ReadonlyNonEmptyArray<A>>
 export function filter<A>(
   predicate: Predicate<A>