diff --git a/docs/modules/Observable.ts.md b/docs/modules/Observable.ts.md
index 7b07b6b..d198ce7 100644
--- a/docs/modules/Observable.ts.md
+++ b/docs/modules/Observable.ts.md
@@ -12,10 +12,10 @@ Added in v0.6.0
 
 <h2 class="text-delta">Table of contents</h2>
 
-- [Alternative](#alternative)
-  - [zero](#zero)
 - [Alt](#alt)
   - [alt](#alt)
+- [Alternative](#alternative)
+  - [zero](#zero)
 - [Applicative](#applicative)
   - [of](#of)
 - [Apply](#apply)
@@ -43,7 +43,7 @@ Added in v0.6.0
   - [fromTask](#fromtask)
 - [instances](#instances)
   - [Alt](#alt-1)
-  - [Alternative](#alternative)
+  - [Alternative](#alternative-1)
   - [Applicative](#applicative-1)
   - [Apply](#apply-1)
   - [Compactable](#compactable-1)
@@ -65,32 +65,32 @@ Added in v0.6.0
 
 ---
 
-# Alternative
+# Alt
 
-## zero
+## alt
+
+Identifies an associative operation on a type constructor. It is similar to `Semigroup`, except that it applies to
+types of kind `* -> *`.
 
 **Signature**
 
 ```ts
-export declare const zero: <A>() => Observable<A>
+export declare const alt: <A>(that: () => Observable<A>) => (fa: Observable<A>) => Observable<A>
 ```
 
-Added in v0.6.12
-
-# Alt
+Added in v0.6.0
 
-## alt
+# Alternative
 
-Identifies an associative operation on a type constructor. It is similar to `Semigroup`, except that it applies to
-types of kind `* -> *`.
+## zero
 
 **Signature**
 
 ```ts
-export declare const alt: <A>(that: () => Observable<A>) => (fa: Observable<A>) => Observable<A>
+export declare const zero: <A>() => Observable<A>
 ```
 
-Added in v0.6.0
+Added in v0.6.12
 
 # Applicative
 
diff --git a/src/Observable.ts b/src/Observable.ts
index 72e9e00..a807b36 100644
--- a/src/Observable.ts
+++ b/src/Observable.ts
@@ -18,7 +18,7 @@ import * as O from 'fp-ts/lib/Option'
 import { pipe } from 'fp-ts/lib/pipeable'
 import { Task } from 'fp-ts/lib/Task'
 import { combineLatest, defer, EMPTY, merge, Observable, of as rxOf } from 'rxjs'
-import { map as rxMap, mergeMap } from 'rxjs/operators'
+import { map as rxMap, switchMap } from 'rxjs/operators'
 import { MonadObservable1 } from './MonadObservable'
 
 // -------------------------------------------------------------------------------------
@@ -107,7 +107,7 @@ export const of: Applicative1<URI>['of'] = rxOf
  * @since 0.6.0
  */
 export const chain: <A, B>(f: (a: A) => Observable<B>) => (ma: Observable<A>) => Observable<B> = f => ma =>
-  ma.pipe(mergeMap(f))
+  ma.pipe(switchMap(f))
 
 /**
  * Derivable from `Monad`.
@@ -152,7 +152,7 @@ export const alt: <A>(that: () => Observable<A>) => (fa: Observable<A>) => Obser
  */
 export const filterMap = <A, B>(f: (a: A) => O.Option<B>) => (fa: Observable<A>): Observable<B> =>
   fa.pipe(
-    mergeMap(a =>
+    switchMap(a =>
       pipe(
         f(a),
         // tslint:disable-next-line: deprecation