diff --git a/Sources/Pageboy.xcodeproj/project.pbxproj b/Sources/Pageboy.xcodeproj/project.pbxproj
index dd9d824f..51171c02 100644
--- a/Sources/Pageboy.xcodeproj/project.pbxproj
+++ b/Sources/Pageboy.xcodeproj/project.pbxproj
@@ -30,8 +30,6 @@
 		464ADF5F20975E5000929AFB /* UIViewController+Pageboy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 464ADF5E20975E5000929AFB /* UIViewController+Pageboy.swift */; };
 		464ADF6020975E5000929AFB /* UIViewController+Pageboy.swift in Sources */ = {isa = PBXBuildFile; fileRef = 464ADF5E20975E5000929AFB /* UIViewController+Pageboy.swift */; };
 		466A76B61FB38B32000B5C1C /* PageboyViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D623B1D11E1D2DF200527F3D /* PageboyViewController.swift */; };
-		468B6FC020EF66A30038E26C /* ScrollObservationService.swift in Sources */ = {isa = PBXBuildFile; fileRef = 468B6FBF20EF66A30038E26C /* ScrollObservationService.swift */; };
-		468B6FC120EF66A30038E26C /* ScrollObservationService.swift in Sources */ = {isa = PBXBuildFile; fileRef = 468B6FBF20EF66A30038E26C /* ScrollObservationService.swift */; };
 		46ADAAB6208F7E1500974529 /* PageboyAutoScroller.swift in Sources */ = {isa = PBXBuildFile; fileRef = 46ADAAB4208F7E1500974529 /* PageboyAutoScroller.swift */; };
 		46ADAAB7208F7E1500974529 /* PageboyAutoScroller.swift in Sources */ = {isa = PBXBuildFile; fileRef = 46ADAAB4208F7E1500974529 /* PageboyAutoScroller.swift */; };
 		46ADAAB8208F7E1500974529 /* PageboyViewController+AutoScrolling.swift in Sources */ = {isa = PBXBuildFile; fileRef = 46ADAAB5208F7E1500974529 /* PageboyViewController+AutoScrolling.swift */; };
@@ -87,7 +85,6 @@
 		464ADF5820975E3D00929AFB /* PageboyViewControllerDelegate.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PageboyViewControllerDelegate.swift; sourceTree = "<group>"; };
 		464ADF5920975E3D00929AFB /* PageboyViewControllerDataSource.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PageboyViewControllerDataSource.swift; sourceTree = "<group>"; };
 		464ADF5E20975E5000929AFB /* UIViewController+Pageboy.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "UIViewController+Pageboy.swift"; sourceTree = "<group>"; };
-		468B6FBF20EF66A30038E26C /* ScrollObservationService.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ScrollObservationService.swift; sourceTree = "<group>"; };
 		46ADAAB4208F7E1500974529 /* PageboyAutoScroller.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PageboyAutoScroller.swift; sourceTree = "<group>"; };
 		46ADAAB5208F7E1500974529 /* PageboyViewController+AutoScrolling.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "PageboyViewController+AutoScrolling.swift"; sourceTree = "<group>"; };
 		46ADAABB208F7E8500974529 /* PageboyViewController+Transitioning.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "PageboyViewController+Transitioning.swift"; sourceTree = "<group>"; };
@@ -271,7 +268,6 @@
 			isa = PBXGroup;
 			children = (
 				462A65D82000FCAA0051C79C /* Extensions */,
-				468B6FBF20EF66A30038E26C /* ScrollObservationService.swift */,
 			);
 			path = Utilities;
 			sourceTree = "<group>";
@@ -485,7 +481,6 @@
 				46ADAAB6208F7E1500974529 /* PageboyAutoScroller.swift in Sources */,
 				464ADF552097565D00929AFB /* Page.swift in Sources */,
 				46ADAAB8208F7E1500974529 /* PageboyViewController+AutoScrolling.swift in Sources */,
-				468B6FC020EF66A30038E26C /* ScrollObservationService.swift in Sources */,
 				462A65E32000FCAA0051C79C /* UIPageViewController+ScrollView.swift in Sources */,
 				46ADAAC2208F7E8500974529 /* TransitionOperation.swift in Sources */,
 				461D6DF1201795A100E0CDEE /* UIScrollView+ScrollActivity.swift in Sources */,
@@ -531,7 +526,6 @@
 				46ADAAB7208F7E1500974529 /* PageboyAutoScroller.swift in Sources */,
 				464ADF562097565D00929AFB /* Page.swift in Sources */,
 				46ADAAB9208F7E1500974529 /* PageboyViewController+AutoScrolling.swift in Sources */,
-				468B6FC120EF66A30038E26C /* ScrollObservationService.swift in Sources */,
 				462A65E42000FCAA0051C79C /* UIPageViewController+ScrollView.swift in Sources */,
 				461D6DF2201795A100E0CDEE /* UIScrollView+ScrollActivity.swift in Sources */,
 				46ADAAC3208F7E8500974529 /* TransitionOperation.swift in Sources */,
diff --git a/Sources/Pageboy/PageboyViewController+Management.swift b/Sources/Pageboy/PageboyViewController+Management.swift
index 4876dbb6..a23e24d7 100644
--- a/Sources/Pageboy/PageboyViewController+Management.swift
+++ b/Sources/Pageboy/PageboyViewController+Management.swift
@@ -98,7 +98,10 @@ internal extension PageboyViewController {
         
         // if not using a custom transition then animate using UIPageViewController mechanism
         let animateUpdate = animated ? !isUsingCustomTransition : false
-        let updateBlock = { [unowned self] in
+        let updateBlock = { [weak self] in
+            guard let self = self else {
+                return
+            }
             pageViewController.setViewControllers(viewControllers,
                                                   direction: direction.layoutNormalized(isRtL: self.view.layoutIsRightToLeft).rawValue,
                                                   animated: animateUpdate,
diff --git a/Sources/Pageboy/Utilities/Extensions/UIView+Localization.swift b/Sources/Pageboy/Utilities/Extensions/UIView+Localization.swift
index c8b15601..8189ab93 100644
--- a/Sources/Pageboy/Utilities/Extensions/UIView+Localization.swift
+++ b/Sources/Pageboy/Utilities/Extensions/UIView+Localization.swift
@@ -12,11 +12,20 @@ extension UIView {
     
     /// Whether the layout direction of the view is right to left.
     var layoutIsRightToLeft: Bool {
-        if #available(iOS 9.0, *) {
-            return UIView.userInterfaceLayoutDirection(for: semanticContentAttribute) == .rightToLeft
+        var layoutDirection: UIUserInterfaceLayoutDirection!
+        if Thread.isMainThread {
+            layoutDirection = getUserInterfaceLayoutDirection()
         } else {
-            return UIApplication.safeShared?.userInterfaceLayoutDirection == .rightToLeft
+            DispatchQueue.main.sync {
+                layoutDirection = getUserInterfaceLayoutDirection()
+            }
         }
+        return layoutDirection == .rightToLeft
+    }
+    
+    private func getUserInterfaceLayoutDirection() -> UIUserInterfaceLayoutDirection {
+        assert(Thread.isMainThread)
+        return UIView.userInterfaceLayoutDirection(for: semanticContentAttribute)
     }
     
 }
diff --git a/Sources/Pageboy/Utilities/ScrollObservationService.swift b/Sources/Pageboy/Utilities/ScrollObservationService.swift
deleted file mode 100644
index 352098f9..00000000
--- a/Sources/Pageboy/Utilities/ScrollObservationService.swift
+++ /dev/null
@@ -1,78 +0,0 @@
-//
-//  ScrollObservationService.swift
-//  Pageboy
-//
-//  Created by Merrick Sapsford on 04/03/2018.
-//  Copyright © 2018 UI At Six. All rights reserved.
-//
-
-import UIKit
-
-internal protocol ScrollObservationServiceDelegate: class {
-    
-    func scrollObservationService(_ service: ScrollObservationService,
-                                  didObserveOffsetChangeFor viewController: UIViewController,
-                                  on scrollView: UIScrollView,
-                                  contentOffset: CGPoint)
-}
-
-internal class ScrollObservationService {
-    
-    private(set) lazy var registrations = [Int: UIViewController]()
-    private var tokens = [Int: NSKeyValueObservation?]()
-    
-    weak var delegate: ScrollObservationServiceDelegate?
-    
-    // MARK: Registration
-    
-    func register(viewController: UIViewController, for index: Int) {
-        if let existingRegistration = registrations[index], existingRegistration === viewController {
-            return
-        }
-        
-        registrations[index] = viewController
-        hook(registration: viewController)
-    }
-    
-    func unregister(index: Int) {
-        if let viewController = registrations[index] {
-            unhook(registration: viewController)
-            registrations.removeValue(forKey: index)
-        }
-    }
-    
-    // MARK: Evaluation
-    
-    private func unhook(registration: UIViewController) {
-        let viewController = registration
-        tokens.removeValue(forKey: viewController.hash)
-    }
-    
-    private func hook(registration: UIViewController) {
-        let viewController = registration
-        for scrollView in viewController.view.scrollViewSubviews {
-            let token = scrollView.observe(\.contentOffset, changeHandler: { [weak self] (scrollView, _) in
-                if let self = self {
-                    self.delegate?.scrollObservationService(self,
-                                                            didObserveOffsetChangeFor: viewController,
-                                                            on: scrollView,
-                                                            contentOffset: scrollView.contentOffset)
-                }
-            })
-            tokens[viewController.hash] = token
-        }
-    }
-}
-
-private extension UIView {
-    
-    var scrollViewSubviews: [UIScrollView] {
-        var scrollViews = [UIScrollView]()
-        subviews.forEach { (subview) in
-            if let scrollView = subview as? UIScrollView {
-                scrollViews.append(scrollView)
-            }
-        }
-        return scrollViews
-    }
-}