diff --git a/RxCocoa/Common/CocoaUnits/Driver/Driver+Operators.swift b/RxCocoa/Common/CocoaUnits/Driver/Driver+Operators.swift
index 6063cb28..ea428d94 100644
--- a/RxCocoa/Common/CocoaUnits/Driver/Driver+Operators.swift
+++ b/RxCocoa/Common/CocoaUnits/Driver/Driver+Operators.swift
@@ -123,7 +123,7 @@ extension DriverConvertibleType {
     public func doOn(_ eventHandler: (Event<E>) -> Void)
         -> Driver<E> {
         let source = self.asObservable()
-            .doOn(eventHandler: eventHandler)
+            .doOn(eventHandler)
         
         return Driver(source)
     }
@@ -137,7 +137,7 @@ extension DriverConvertibleType {
     - returns: The source sequence with the side-effecting behavior applied.
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOn(_ onNext: ((E) -> Void)? = nil, onError: ((ErrorProtocol) -> Void)? = nil, onCompleted: (() -> Void)? = nil)
+    public func doOn(onNext: ((E) -> Void)? = nil, onError: ((ErrorProtocol) -> Void)? = nil, onCompleted: (() -> Void)? = nil)
         -> Driver<E> {
         let source = self.asObservable()
             .doOn(onNext: onNext, onError: onError, onCompleted: onCompleted)
@@ -152,9 +152,9 @@ extension DriverConvertibleType {
      - returns: The source sequence with the side-effecting behavior applied.
      */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOnNext(_ onNext: ((E) -> Void))
+    public func `do`(onNext: ((E) -> Void))
         -> Driver<E> {
-        return self.doOn(onNext)
+        return self.doOn(onNext: onNext)
     }
 
     /**
@@ -164,7 +164,7 @@ extension DriverConvertibleType {
      - returns: The source sequence with the side-effecting behavior applied.
      */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOnCompleted(_ onCompleted: (() -> Void))
+    public func `do`(onCompleted: (() -> Void))
         -> Driver<E> {
         return self.doOn(onCompleted: onCompleted)
     }
@@ -399,7 +399,7 @@ extension Collection where Iterator.Element : DriverConvertibleType {
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
     public func zip<R>(_ resultSelector: ([Generator.Element.E]) throws -> R) -> Driver<R> {
-        let source = self.map { $0.asDriver().asObservable() }.zip(resultSelector: resultSelector)
+        let source = self.map { $0.asDriver().asObservable() }.zip(resultSelector)
         return Driver<R>(source)
     }
 }
@@ -415,7 +415,7 @@ extension Collection where Iterator.Element : DriverConvertibleType {
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
     public func combineLatest<R>(_ resultSelector: ([Generator.Element.E]) throws -> R) -> Driver<R> {
-        let source = self.map { $0.asDriver().asObservable() }.combineLatest(resultSelector: resultSelector)
+        let source = self.map { $0.asDriver().asObservable() }.combineLatest(resultSelector)
         return Driver<R>(source)
     }
 }
diff --git a/RxExample/RxExample/Services/ImageService.swift b/RxExample/RxExample/Services/ImageService.swift
index 1f3a7eb9..82ca0057 100644
--- a/RxExample/RxExample/Services/ImageService.swift
+++ b/RxExample/RxExample/Services/ImageService.swift
@@ -75,17 +75,17 @@ class DefaultImageService: ImageService {
                     else {
                         // fetch from network
                         decodedImage = self.$.URLSession.rx_data(URLRequest(url: url))
-                            .doOnNext { data in
+                            .do(onNext: { data in
                                 self._imageDataCache.setObject(data, forKey: url)
-                            }
+                            })
                             .flatMap(self.decodeImage)
                             .trackActivity(self.loadingImage)
                     }
                 }
                 
-                return decodedImage.doOnNext { image in
+                return decodedImage.do(onNext: { image in
                     self._imageCache.setObject(image, forKey: url)
-                }
+                })
             }
     }
 
diff --git a/RxSwift/Observables/Observable+Multiple.swift b/RxSwift/Observables/Observable+Multiple.swift
index 9a646de5..7190495c 100644
--- a/RxSwift/Observables/Observable+Multiple.swift
+++ b/RxSwift/Observables/Observable+Multiple.swift
@@ -21,7 +21,7 @@ extension Collection where Iterator.Element : ObservableType {
     - returns: An observable sequence containing the result of combining elements of the sources using the specified result selector function.
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func combineLatest<R>(resultSelector: ([Generator.Element.E]) throws -> R) -> Observable<R> {
+    public func combineLatest<R>(_ resultSelector: ([Generator.Element.E]) throws -> R) -> Observable<R> {
         return CombineLatestCollectionType(sources: self, resultSelector: resultSelector)
     }
 }
@@ -39,7 +39,7 @@ extension Collection where Iterator.Element : ObservableType {
     - returns: An observable sequence containing the result of combining elements of the sources using the specified result selector function.
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func zip<R>(resultSelector: ([Generator.Element.E]) throws -> R) -> Observable<R> {
+    public func zip<R>(_ resultSelector: ([Generator.Element.E]) throws -> R) -> Observable<R> {
         return ZipCollectionType(sources: self, resultSelector: resultSelector)
     }
 }
diff --git a/RxSwift/Observables/Observable+Single.swift b/RxSwift/Observables/Observable+Single.swift
index 784fd4a0..4ed98d6a 100644
--- a/RxSwift/Observables/Observable+Single.swift
+++ b/RxSwift/Observables/Observable+Single.swift
@@ -84,7 +84,7 @@ extension ObservableType {
     - returns: The source sequence with the side-effecting behavior applied.
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOn(eventHandler: (Event<E>) throws -> Void)
+    public func doOn(_ eventHandler: (Event<E>) throws -> Void)
         -> Observable<E> {
         return Do(source: self.asObservable(), eventHandler: eventHandler)
     }
@@ -121,7 +121,7 @@ extension ObservableType {
      - returns: The source sequence with the side-effecting behavior applied.
      */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOnNext(onNext: ((E) throws -> Void))
+    public func `do`(onNext: ((E) throws -> Void))
         -> Observable<E> {
         return self.doOn(onNext: onNext)
     }
@@ -133,7 +133,7 @@ extension ObservableType {
      - returns: The source sequence with the side-effecting behavior applied.
      */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOnError(onError: ((ErrorProtocol) throws -> Void))
+    public func `do`(onError: ((ErrorProtocol) throws -> Void))
         -> Observable<E> {
         return self.doOn(onError: onError)
     }
@@ -145,7 +145,7 @@ extension ObservableType {
      - returns: The source sequence with the side-effecting behavior applied.
      */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func doOnCompleted(onCompleted: (() throws -> Void))
+    public func `do`(onCompleted: (() throws -> Void))
         -> Observable<E> {
         return self.doOn(onCompleted: onCompleted)
     }
@@ -229,7 +229,7 @@ extension ObservableType {
     - returns: An observable sequence producing the elements of the given sequence repeatedly until it terminates successfully or is notified to error or complete.
     */
     // @warn_unused_result(message:"http://git.io/rxs.uo")
-    public func retryWhen<TriggerObservable: ObservableType>(notificationHandler: (Observable<ErrorProtocol>) -> TriggerObservable)
+    public func retryWhen<TriggerObservable: ObservableType>(_ notificationHandler: (Observable<ErrorProtocol>) -> TriggerObservable)
         -> Observable<E> {
             return RetryWhenSequence(sources: InfiniteSequence(repeatedValue: self.asObservable()), notificationHandler: notificationHandler)
     }
diff --git a/Tests/RxCocoaTests/Driver+Test.swift b/Tests/RxCocoaTests/Driver+Test.swift
index c90ca678..58803b04 100644
--- a/Tests/RxCocoaTests/Driver+Test.swift
+++ b/Tests/RxCocoaTests/Driver+Test.swift
@@ -548,10 +548,10 @@ extension DriverTest {
 
         var events = [Int]()
 
-        let driver = hotObservable.asDriver(onErrorJustReturn: -1).doOnNext { e in
+        let driver = hotObservable.asDriver(onErrorJustReturn: -1).do(onNext: { e in
             XCTAssertTrue(isMainThread())
             events.append(e)
-        }
+        })
 
         let results = subscribeTwiceOnBackgroundSchedulerAndOnlyOneSubscription(driver) {
             XCTAssertTrue(hotObservable.subscriptions == [SubscribedToHotObservable])
@@ -572,10 +572,10 @@ extension DriverTest {
         let hotObservable = BackgroundThreadPrimitiveHotObservable<Int>()
 
         var completed = false
-        let driver = hotObservable.asDriver(onErrorJustReturn: -1).doOnCompleted { e in
+        let driver = hotObservable.asDriver(onErrorJustReturn: -1).do(onCompleted: { e in
             XCTAssertTrue(isMainThread())
             completed = true
-        }
+        })
 
         let results = subscribeTwiceOnBackgroundSchedulerAndOnlyOneSubscription(driver) {
             XCTAssertTrue(hotObservable.subscriptions == [SubscribedToHotObservable])
diff --git a/Tests/RxSwiftTests/Tests/Observable+SingleTest.swift b/Tests/RxSwiftTests/Tests/Observable+SingleTest.swift
index 668103c5..a682e3c5 100644
--- a/Tests/RxSwiftTests/Tests/Observable+SingleTest.swift
+++ b/Tests/RxSwiftTests/Tests/Observable+SingleTest.swift
@@ -573,9 +573,9 @@ extension ObservableSingleTest {
 
         var numberOfTimesInvoked = 0
 
-        let res = scheduler.start { xs.doOnNext { error in
+        let res = scheduler.start { xs.do(onNext: { error in
                 numberOfTimesInvoked = numberOfTimesInvoked + 1
-            }
+            })
         }
 
         let correctMessages = [
@@ -610,12 +610,12 @@ extension ObservableSingleTest {
 
         var numberOfTimesInvoked = 0
 
-        let res = scheduler.start { xs.doOnNext { error in
+        let res = scheduler.start { xs.do(onNext: { error in
                 if numberOfTimesInvoked > 2 {
                     throw testError
                 }
                 numberOfTimesInvoked = numberOfTimesInvoked + 1
-            }
+            })
         }
 
         let correctMessages = [
@@ -647,10 +647,10 @@ extension ObservableSingleTest {
         var recordedError: ErrorProtocol!
         var numberOfTimesInvoked = 0
 
-        let res = scheduler.start { xs.doOnError { error in
+        let res = scheduler.start { xs.do(onError: { error in
                 recordedError = error
                 numberOfTimesInvoked = numberOfTimesInvoked + 1
-            }
+            })
         }
 
         let correctMessages = [
@@ -678,9 +678,9 @@ extension ObservableSingleTest {
             error(250, testError)
             ])
 
-        let res = scheduler.start { xs.doOnError { _ in
+        let res = scheduler.start { xs.do(onError: { _ in
                 throw testError1
-            }
+            })
         }
 
         let correctMessages = [
@@ -710,9 +710,9 @@ extension ObservableSingleTest {
 
         var didComplete = false
 
-        let res = scheduler.start { xs.doOnCompleted { error in
+        let res = scheduler.start { xs.do(onCompleted: { error in
                 didComplete = true
-            }
+            })
         }
 
         let correctMessages = [
@@ -745,9 +745,9 @@ extension ObservableSingleTest {
             completed(250)
             ])
 
-        let res = scheduler.start { xs.doOnCompleted { error in
+        let res = scheduler.start { xs.do(onCompleted: { error in
                 throw testError
-            }
+            })
         }
 
         let correctMessages = [