diff --git a/Source/AuthenticatedWebViewController.swift b/Source/AuthenticatedWebViewController.swift
index 93fbe84b7..7aeec4eaa 100644
--- a/Source/AuthenticatedWebViewController.swift
+++ b/Source/AuthenticatedWebViewController.swift
@@ -457,6 +457,15 @@ public class AuthenticatedWebViewController: UIViewController, WKUIDelegate, WKN
         return requestURL.contains(type.rawValue)
     }
     
+    public func removeCallbackHandler() {
+        configurations.userContentController.removeAllUserScripts()
+        if #available(iOS 14.0, *) {
+            configurations.userContentController.removeAllScriptMessageHandlers()
+        } else {
+            configurations.userContentController.removeScriptMessageHandler(forName: AJAXCallBackHandler)
+        }
+    }
+    
     public func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
         if message.name == AJAXCallBackHandler {
             guard let data = message.body as? Dictionary<AnyHashable, Any> else { return }
diff --git a/Source/CourseDatesViewController.swift b/Source/CourseDatesViewController.swift
index 0e922ac00..c3f984864 100644
--- a/Source/CourseDatesViewController.swift
+++ b/Source/CourseDatesViewController.swift
@@ -25,7 +25,6 @@ class CourseDatesViewController: UIViewController, InterfaceOrientationOverridin
     
     private let datesLoader = BackedStream<(CourseDateModel, UserPreference?)>()
     private let courseDateBannerLoader = BackedStream<(CourseDateBannerModel)>()
-    private var stream: OEXStream<(CourseDateModel, UserPreference?)>?
     
     private lazy var tableView: UITableView = {
         let tableView = UITableView()
@@ -177,10 +176,10 @@ class CourseDatesViewController: UIViewController, InterfaceOrientationOverridin
         let preferenceStream = environment.dataManager.userPreferenceManager.feed.output
         let networkRequest = CourseDatesAPI.courseDatesRequest(courseID: courseID)
         let datesStream = environment.networkManager.streamForRequest(networkRequest)
-        stream = joinStreams(datesStream, preferenceStream)
-        datesLoader.addBackingStream(datesLoader)
+        let stream = joinStreams(datesStream, preferenceStream)
+        datesLoader.addBackingStream(stream)
         
-        stream?.listen(self) { [weak self] response in
+        stream.listen(self) { [weak self] response in
             self?.refreshController.endRefreshing()
             switch response {
             case .success((var courseDateModel, let userPreference)):
diff --git a/Source/HTMLBlockViewController.swift b/Source/HTMLBlockViewController.swift
index 476e71b71..d4d1c71ef 100644
--- a/Source/HTMLBlockViewController.swift
+++ b/Source/HTMLBlockViewController.swift
@@ -253,6 +253,7 @@ class HTMLBlockViewController: UIViewController, CourseBlockViewController, Prel
     }
     
     deinit {
+        webController.removeCallbackHandler()
         NotificationCenter.default.removeObserver(self)
     }
 }