diff --git a/PyCon-JP/DataSource/More/StaffListDataSource.swift b/PyCon-JP/DataSource/More/StaffListDataSource.swift
index 0118b47..c0ea6f0 100644
--- a/PyCon-JP/DataSource/More/StaffListDataSource.swift
+++ b/PyCon-JP/DataSource/More/StaffListDataSource.swift
@@ -22,7 +22,7 @@ class StaffListDataSource: NSObject, UITableViewDataSource, StaffListAPIProtocol
         self.twitterAction = twitterAction
     }
     
-    func refreshData(completionHandler: @escaping ((Result<Void>) -> Void)) -> Void {
+    func refreshData(completionHandler: @escaping ((Result<Void>) -> Void)) {
         getStaffs { [weak self](result) in
             guard let weakSelf = self else { return }
             switch result {
diff --git a/PyCon-JP/DataSource/Timeline/Bookmark/BookmarkListDataSource.swift b/PyCon-JP/DataSource/Timeline/Bookmark/BookmarkListDataSource.swift
index c86c905..d2abcab 100644
--- a/PyCon-JP/DataSource/Timeline/Bookmark/BookmarkListDataSource.swift
+++ b/PyCon-JP/DataSource/Timeline/Bookmark/BookmarkListDataSource.swift
@@ -14,7 +14,7 @@ class BookmarkListDataSource: TimelineDataSource, RealmTalksProtocol {
     let filterPredicate = NSPredicate(format: "favorited == %@", true as CVarArg)
     let sortProperties = [SortDescriptor(property: "date", ascending: true), SortDescriptor(property: "place", ascending: true)]
     
-    func refreshData(completionHandler: @escaping ((Result<Void>) -> Void)) -> Void {
+    func refreshData(completionHandler: @escaping ((Result<Void>) -> Void)) {
         loadTalkObjects { [weak self](result) in
             guard let weakSelf = self else { return }
             switch result {
diff --git a/PyCon-JP/DataSource/Timeline/Conference/ConferenceListDataSource.swift b/PyCon-JP/DataSource/Timeline/Conference/ConferenceListDataSource.swift
index e8dd632..24e4e1f 100644
--- a/PyCon-JP/DataSource/Timeline/Conference/ConferenceListDataSource.swift
+++ b/PyCon-JP/DataSource/Timeline/Conference/ConferenceListDataSource.swift
@@ -19,7 +19,7 @@ class ConferenceListDataSource: TimelineDataSource, RealmTalksProtocol {
         super.init()
     }
     
-    func refreshData(completionHandler: @escaping ((Result<Void>) -> Void)) -> Void {
+    func refreshData(completionHandler: @escaping ((Result<Void>) -> Void)) {
         loadTalkObjects { [weak self](result) in
             guard let weakSelf = self else { return }
             switch result {
diff --git a/PyCon-JP/Manager/Notification/LocalNotificationManager.swift b/PyCon-JP/Manager/Notification/LocalNotificationManager.swift
index 13447ed..b0c68ad 100644
--- a/PyCon-JP/Manager/Notification/LocalNotificationManager.swift
+++ b/PyCon-JP/Manager/Notification/LocalNotificationManager.swift
@@ -45,7 +45,7 @@ class LocalNotificationManager: NSObject {
     
     func cancelSchedule(talkDetail: TalkDetail) {
         if let localNotifications = UIApplication.shared.scheduledLocalNotifications {
-            localNotifications.forEach({ (notification) -> () in
+            localNotifications.forEach({ notification in
                 if let userInfo = notification.userInfo {
                     if userInfo["id"] as! Int == talkDetail.talkObject.id {
                         UIApplication.shared.cancelLocalNotification(notification)
diff --git a/PyCon-JP/Manager/Notification/ReceiveLocalNotificationManager.swift b/PyCon-JP/Manager/Notification/ReceiveLocalNotificationManager.swift
index 6bb8ef1..19c55eb 100644
--- a/PyCon-JP/Manager/Notification/ReceiveLocalNotificationManager.swift
+++ b/PyCon-JP/Manager/Notification/ReceiveLocalNotificationManager.swift
@@ -16,7 +16,7 @@ class ReceiveLocalNotificationManager: NSObject {
         case "Talk" where application.applicationState == .active:
             let alertController = UIAlertController(title: "", message: "", preferredStyle: .alert)
             alertController.addAction(UIAlertAction(title: "閉じる", style: .default, handler: nil))
-            alertController.addAction(UIAlertAction(title: "詳細へ", style: .default, handler: {(action) -> Void in
+            alertController.addAction(UIAlertAction(title: "詳細へ", style: .default, handler: { _ -> Void in
                 appDelegate.openTalkDetailViewController(id: id)
             }))
             if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
diff --git a/PyCon-JP/Protocol/ErrorAlertProtocol.swift b/PyCon-JP/Protocol/ErrorAlertProtocol.swift
index e184982..c1cabf7 100644
--- a/PyCon-JP/Protocol/ErrorAlertProtocol.swift
+++ b/PyCon-JP/Protocol/ErrorAlertProtocol.swift
@@ -9,12 +9,12 @@
 import UIKit
 
 protocol ErrorAlertProtocol {
-    func showErrorAlart(with error: Error, parent viewController: UIViewController?) -> Void
+    func showErrorAlart(with error: Error, parent viewController: UIViewController?)
 }
 
 extension ErrorAlertProtocol {
     
-    func showErrorAlart(with error: Error, parent viewController: UIViewController? = nil) -> Void {
+    func showErrorAlart(with error: Error, parent viewController: UIViewController? = nil) {
         
         let rootViewController = viewController != nil ? viewController! : UIApplication.shared.keyWindow!.rootViewController!
         
diff --git a/PyCon-JP/Protocol/Realm/RealmTalkDetailProtocol.swift b/PyCon-JP/Protocol/Realm/RealmTalkDetailProtocol.swift
index b377bd0..857476a 100644
--- a/PyCon-JP/Protocol/Realm/RealmTalkDetailProtocol.swift
+++ b/PyCon-JP/Protocol/Realm/RealmTalkDetailProtocol.swift
@@ -9,12 +9,12 @@
 import UIKit
 
 protocol RealmTalkDetailProtocol {
-    func getTalksFromLocalDummyJson(completionHandler: ((Result<Void>) -> Void)) -> Void
+    func getTalksFromLocalDummyJson(completionHandler: ((Result<Void>) -> Void))
 }
 
 extension RealmTalkDetailProtocol {
     
-    func getTalkDetailFromLocalDummyJson(completionHandler: ((Result<TalkDetail>) -> Void)) -> Void {
+    func getTalkDetailFromLocalDummyJson(completionHandler: ((Result<TalkDetail>) -> Void)) {
         let path = Bundle.main.path(forResource: "DummyTalkDetail", ofType: "json")
         let fileHandle = FileHandle(forReadingAtPath: path!)
         let data = fileHandle?.readDataToEndOfFile()
diff --git a/PyCon-JP/Protocol/Realm/RealmTalksProtocol.swift b/PyCon-JP/Protocol/Realm/RealmTalksProtocol.swift
index 353a4c1..099be55 100644
--- a/PyCon-JP/Protocol/Realm/RealmTalksProtocol.swift
+++ b/PyCon-JP/Protocol/Realm/RealmTalksProtocol.swift
@@ -13,13 +13,13 @@ protocol RealmTalksProtocol {
     var filterPredicate: NSPredicate { get }
     var sortProperties: [SortDescriptor] { get }
     
-    func loadTalkObjects(_ completionHandler: ((Result<[TalkObject]>) -> Void)) -> Void
-    func getTalksFromLocalDummyJson(completionHandler: ((Result<Void>) -> Void)) -> Void
+    func loadTalkObjects(_ completionHandler: ((Result<[TalkObject]>) -> Void))
+    func getTalksFromLocalDummyJson(completionHandler: ((Result<Void>) -> Void))
 }
 
 extension RealmTalksProtocol {
     
-    func loadTalkObjects(_ completionHandler: ((Result<[TalkObject]>) -> Void)) -> Void {
+    func loadTalkObjects(_ completionHandler: ((Result<[TalkObject]>) -> Void)) {
         do {
             let realm = try Realm()
             let talks = Array(realm.objects(TalkObject.self).filter(filterPredicate).sorted(by: sortProperties))
@@ -33,7 +33,7 @@ extension RealmTalksProtocol {
 
 extension RealmTalksProtocol {
     
-    func getTalksFromLocalDummyJson(completionHandler: ((Result<Void>) -> Void)) -> Void {
+    func getTalksFromLocalDummyJson(completionHandler: ((Result<Void>) -> Void)) {
         let path = Bundle.main.path(forResource: "DummyTalks", ofType: "json")
         let fileHandle = FileHandle(forReadingAtPath: path!)
         let data = fileHandle?.readDataToEndOfFile()
diff --git a/PyCon-JP/Protocol/URLScheme/TwitterURLSchemeProtocol.swift b/PyCon-JP/Protocol/URLScheme/TwitterURLSchemeProtocol.swift
index 85245c6..33fbdc1 100644
--- a/PyCon-JP/Protocol/URLScheme/TwitterURLSchemeProtocol.swift
+++ b/PyCon-JP/Protocol/URLScheme/TwitterURLSchemeProtocol.swift
@@ -11,8 +11,8 @@ import SafariServices
 
 protocol TwitterURLSchemeProtocol {
     
-    func openTwitter(userName: String, from viewController: UIViewController, alertBefore: Bool) -> Void
-    func openTwitter(hashTag: String, from viewController: UIViewController, alertBefore: Bool) -> Void
+    func openTwitter(userName: String, from viewController: UIViewController, alertBefore: Bool)
+    func openTwitter(hashTag: String, from viewController: UIViewController, alertBefore: Bool)
     
 }
 
@@ -26,14 +26,14 @@ extension TwitterURLSchemeProtocol {
         let alertController = UIAlertController(title: NSLocalizedString("TwitterAlertTitle", tableName: "URLScheme", comment: ""),
                                                 message: String(format: NSLocalizedString("TwitterAlertMessage", tableName: "URLScheme", comment: ""), arguments: [targetName]),
                                                 preferredStyle: .alert)
-        alertController.addAction(UIAlertAction(title: NSLocalizedString("Open", comment: ""), style: .default, handler: { action in
+        alertController.addAction(UIAlertAction(title: NSLocalizedString("Open", comment: ""), style: .default, handler: { _ in
             UIApplication.shared.openURL(url)
         }))
         alertController.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: ""), style: .cancel, handler: nil))
         viewController.present(alertController, animated: true, completion: nil)
     }
     
-    func openTwitter(userName: String, from viewController: UIViewController, alertBefore: Bool = false) -> Void {
+    func openTwitter(userName: String, from viewController: UIViewController, alertBefore: Bool = false) {
         if UIApplication.shared.canOpenURL(urlScheme) {
             guard let url = URL(string: "twitter://user?screen_name=" + userName) else { return }
             if alertBefore {
@@ -48,7 +48,7 @@ extension TwitterURLSchemeProtocol {
         }
     }
     
-    func openTwitter(hashTag: String, from viewController: UIViewController, alertBefore: Bool = false) -> Void {
+    func openTwitter(hashTag: String, from viewController: UIViewController, alertBefore: Bool = false) {
         if UIApplication.shared.canOpenURL(urlScheme) {
             guard let url = URL(string: "twitter://search?query=%23" + hashTag) else { return }
             if alertBefore {
diff --git a/PyCon-JP/Protocol/WebAPI/StaffListAPIProtocol.swift b/PyCon-JP/Protocol/WebAPI/StaffListAPIProtocol.swift
index 9b8b563..363d977 100644
--- a/PyCon-JP/Protocol/WebAPI/StaffListAPIProtocol.swift
+++ b/PyCon-JP/Protocol/WebAPI/StaffListAPIProtocol.swift
@@ -10,7 +10,7 @@ import UIKit
 import WebAPIFramework
 
 protocol StaffListAPIProtocol: AlamofireProtocol {
-    func getStaffs(completionHandler: @escaping ((Result<[Staff]>) -> Void)) -> Void
+    func getStaffs(completionHandler: @escaping ((Result<[Staff]>) -> Void))
 }
 
 extension StaffListAPIProtocol {
@@ -27,8 +27,8 @@ extension StaffListAPIProtocol {
 
 extension StaffListAPIProtocol {
     
-    func getStaffs(completionHandler: @escaping ((Result<[Staff]>) -> Void)) -> Void {
-        get() { result in
+    func getStaffs(completionHandler: @escaping ((Result<[Staff]>) -> Void)) {
+        get { result in
             switch result {
             case .success(let value):
                 let staffList = value["staffList"] as? [[String: Any]] ?? []
diff --git a/PyCon-JP/Protocol/WebAPI/TalkDetailAPIProtocol.swift b/PyCon-JP/Protocol/WebAPI/TalkDetailAPIProtocol.swift
index e5b17a4..33ef277 100644
--- a/PyCon-JP/Protocol/WebAPI/TalkDetailAPIProtocol.swift
+++ b/PyCon-JP/Protocol/WebAPI/TalkDetailAPIProtocol.swift
@@ -12,7 +12,7 @@ import WebAPIFramework
 protocol TalkDetailAPIProtocol: AlamofireProtocol {
     var id: Int? { get set }
     
-    func getTalkDetail(completionHandler: @escaping ((Result<TalkDetail>) -> Void)) -> Void
+    func getTalkDetail(completionHandler: @escaping ((Result<TalkDetail>) -> Void))
 }
 
 extension TalkDetailAPIProtocol {
@@ -26,8 +26,8 @@ extension TalkDetailAPIProtocol {
 
 extension TalkDetailAPIProtocol {
     
-    func getTalkDetail(completionHandler: @escaping ((Result<TalkDetail>) -> Void)) -> Void {
-        get() { result in
+    func getTalkDetail(completionHandler: @escaping ((Result<TalkDetail>) -> Void)) {
+        get { result in
             switch result {
             case .success(let value):
                 let talkDetail = TalkDetail(dictionary: value)
diff --git a/PyCon-JP/Protocol/WebAPI/TalksAPIProtocol.swift b/PyCon-JP/Protocol/WebAPI/TalksAPIProtocol.swift
index 9f1a400..ecbd2fc 100644
--- a/PyCon-JP/Protocol/WebAPI/TalksAPIProtocol.swift
+++ b/PyCon-JP/Protocol/WebAPI/TalksAPIProtocol.swift
@@ -11,7 +11,7 @@ import WebAPIFramework
 import RealmSwift
 
 protocol TalksAPIProtocol: AlamofireProtocol {
-    func getTalks(completionHandler: @escaping ((Result<Void>) -> Void)) -> Void
+    func getTalks(completionHandler: @escaping ((Result<Void>) -> Void))
 }
 
 extension TalksAPIProtocol {
@@ -24,8 +24,8 @@ extension TalksAPIProtocol {
 
 extension TalksAPIProtocol {
     
-    func getTalks(completionHandler: @escaping ((Result<Void>) -> Void)) -> Void {
-        get() { result in
+    func getTalks(completionHandler: @escaping ((Result<Void>) -> Void)) {
+        get { result in
             switch result {
             case .success(let value):
                 let presentations = value["presentations"] as? [[String: Any]] ?? [[String: Any]]()
diff --git a/PyCon-JP/ViewController/Base/ZoomableImageViewController.swift b/PyCon-JP/ViewController/Base/ZoomableImageViewController.swift
index 76031f7..cfbda25 100644
--- a/PyCon-JP/ViewController/Base/ZoomableImageViewController.swift
+++ b/PyCon-JP/ViewController/Base/ZoomableImageViewController.swift
@@ -51,7 +51,7 @@ class ZoomableImageViewController: UIViewController, UIScrollViewDelegate {
         if toHidden {
             UIView.animate(withDuration: 0.2, animations: {
                 self.toolBar.alpha = 0
-                }, completion: { finished in
+                }, completion: { _ in
                     self.toolBar.isHidden = true
             })
         } else {
diff --git a/PyCon-JP/ViewController/Conference/ConferencePageViewController.swift b/PyCon-JP/ViewController/Conference/ConferencePageViewController.swift
index 36e66bc..cb461c9 100644
--- a/PyCon-JP/ViewController/Conference/ConferencePageViewController.swift
+++ b/PyCon-JP/ViewController/Conference/ConferencePageViewController.swift
@@ -17,13 +17,13 @@ class ConferencePageViewController: UIPageViewController, ConferencePageViewProt
         
         let startingViewController = self.conferenceModelController.viewController(index: 0, storyboard: self.storyboard!)!
         let viewControllers = [startingViewController]
-        self.setViewControllers(viewControllers, direction: .forward, animated: false, completion: {done in })
+        self.setViewControllers(viewControllers, direction: .forward, animated: false)
         
         self.dataSource = self.conferenceModelController
         
     }
     
-    private var _conferenceModelController: ConferenceModelController? = nil
+    private var _conferenceModelController: ConferenceModelController?
     
     private var conferenceModelController: ConferenceModelController {
         if _conferenceModelController == nil {
@@ -61,7 +61,7 @@ class ConferencePageViewController: UIPageViewController, ConferencePageViewProt
     private func movePage(index: Int, direction: UIPageViewControllerNavigationDirection) {
         let viewController = conferenceModelController.viewController(index: index, storyboard: self.storyboard!)!
         let viewControllers = [viewController]
-        self.setViewControllers(viewControllers, direction: direction, animated: true, completion: {done in})
+        self.setViewControllers(viewControllers, direction: direction, animated: true)
     }
     
 }
diff --git a/WebAPIFramework/Alamofire/AlamofireProtocol.swift b/WebAPIFramework/Alamofire/AlamofireProtocol.swift
index a29f621..5e6791f 100644
--- a/WebAPIFramework/Alamofire/AlamofireProtocol.swift
+++ b/WebAPIFramework/Alamofire/AlamofireProtocol.swift
@@ -15,7 +15,7 @@ public protocol AlamofireProtocol {
     var authUser: String { get }
     var authPassword: String { get }
     
-    func get(parameter: [String: Any]?, completionHandler: @escaping ((Result<[String: Any]>) -> Void)) -> Void
+    func get(parameter: [String: Any]?, completionHandler: @escaping ((Result<[String: Any]>) -> Void))
 }
 
 public extension AlamofireProtocol {
@@ -36,7 +36,7 @@ public extension AlamofireProtocol {
 
 public extension AlamofireProtocol {
     
-    func get(parameter: [String: Any]? = nil, completionHandler: @escaping ((Result<[String: Any]>) -> Void)) -> Void {
+    func get(parameter: [String: Any]? = nil, completionHandler: @escaping ((Result<[String: Any]>) -> Void)) {
         let url = baseURL + path
         let responseClosure = { (response: DataResponse<Any>) in
             switch response.result {