diff --git a/src/add/operator/catch.ts b/src/add/operator/catch.ts
index 2451d40dbf..52bdea2f07 100644
--- a/src/add/operator/catch.ts
+++ b/src/add/operator/catch.ts
@@ -3,9 +3,11 @@ import { Observable } from '../../Observable';
 import { _catch, CatchSignature } from '../../operator/catch';
 
 Observable.prototype.catch = _catch;
+Observable.prototype._catch = _catch;
 
 declare module '../../Observable' {
   interface Observable<T> {
     catch: CatchSignature<T>;
+    _catch: CatchSignature<T>;
   }
 }
\ No newline at end of file
diff --git a/src/add/operator/do.ts b/src/add/operator/do.ts
index 53f0d8598b..6fe67140c0 100644
--- a/src/add/operator/do.ts
+++ b/src/add/operator/do.ts
@@ -3,9 +3,11 @@ import { Observable } from '../../Observable';
 import { _do, DoSignature } from '../../operator/do';
 
 Observable.prototype.do = _do;
+Observable.prototype._do = _do;
 
 declare module '../../Observable' {
   interface Observable<T> {
     do: DoSignature<T>;
+    _do: DoSignature<T>;
   }
 }
\ No newline at end of file
diff --git a/src/add/operator/finally.ts b/src/add/operator/finally.ts
index 33b6fe410d..471a255557 100644
--- a/src/add/operator/finally.ts
+++ b/src/add/operator/finally.ts
@@ -3,9 +3,11 @@ import { Observable } from '../../Observable';
 import { _finally, FinallySignature } from '../../operator/finally';
 
 Observable.prototype.finally = _finally;
+Observable.prototype._finally = _finally;
 
 declare module '../../Observable' {
   interface Observable<T> {
     finally: FinallySignature<T>;
+    _finally: FinallySignature<T>;
   }
 }
\ No newline at end of file
diff --git a/src/add/operator/switch.ts b/src/add/operator/switch.ts
index 311cc049f9..af6a8fb813 100644
--- a/src/add/operator/switch.ts
+++ b/src/add/operator/switch.ts
@@ -3,9 +3,11 @@ import { Observable } from '../../Observable';
 import { _switch, SwitchSignature } from '../../operator/switch';
 
 Observable.prototype.switch = _switch;
+Observable.prototype._switch = _switch;
 
 declare module '../../Observable' {
   interface Observable<T> {
     switch: SwitchSignature<T>;
+    _switch: SwitchSignature<T>;
   }
 }
\ No newline at end of file