diff --git a/CHANGELOG.md b/CHANGELOG.md
index 37593a2..f6b45ff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,16 +1,7 @@
 # CHANGELOG
+### v1.1.1
+- Fixed crash problem using WKWebView's scrollview. #18
 
-## *Unreleased*
-
-#### Added
-
-#### Removed
-
-#### Updated
-
-#### Fixed
-
-## **Released**
 ### v1.1
 #### Added
 - Edge shadow #9
diff --git a/PullToDismiss.podspec b/PullToDismiss.podspec
index 5341417..f20adb5 100644
--- a/PullToDismiss.podspec
+++ b/PullToDismiss.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "PullToDismiss"
-  s.version          = "1.1"
+  s.version          = "1.1.1"
   s.summary          = "Dismiss ViewController by pulling scroll view or navigation bar in Swift."
   s.homepage         = "https://github.com/sgr-ksmt/PullToDismiss"
   # s.screenshots     = ""
diff --git a/Sources/PullToDismiss.swift b/Sources/PullToDismiss.swift
index 1bca6e7..5640f89 100644
--- a/Sources/PullToDismiss.swift
+++ b/Sources/PullToDismiss.swift
@@ -32,6 +32,7 @@ open class PullToDismiss: NSObject {
     fileprivate var previousContentOffsetY: CGFloat = 0.0
     fileprivate weak var viewController: UIViewController?
     
+    private var __scrollView: UIScrollView?
     private var panGesture: UIPanGestureRecognizer?
     private var backgroundView: UIView?
     private var navigationBarHeight: CGFloat = 0.0
@@ -47,6 +48,7 @@ open class PullToDismiss: NSObject {
     public init(scrollView: UIScrollView, viewController: UIViewController, navigationBar: UIView? = nil) {
         super.init()
         scrollView.delegate = self
+        __scrollView = scrollView
         self.viewController = viewController
         if let navigationBar = navigationBar ?? viewController.navigationController?.navigationBar {
             let gesture = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture(_:)))
@@ -60,6 +62,9 @@ open class PullToDismiss: NSObject {
         if let panGesture = panGesture {
             panGesture.view?.removeGestureRecognizer(panGesture)
         }
+        
+        __scrollView?.delegate = nil
+        __scrollView = nil
     }
     
     fileprivate var targetViewController: UIViewController? {