diff --git a/Signal/src/ViewControllers/DebugUI/DebugUINotifications.swift b/Signal/src/ViewControllers/DebugUI/DebugUINotifications.swift
index f9d810acf..966c5dd65 100644
--- a/Signal/src/ViewControllers/DebugUI/DebugUINotifications.swift
+++ b/Signal/src/ViewControllers/DebugUI/DebugUINotifications.swift
@@ -36,11 +36,15 @@ class DebugUINotifications: DebugUIPage {
         }
 
         var sectionItems = [
-            OWSTableItem(title:"Last Incoming Message") {
-                Logger.info("\(self.logTag) scheduling notification for incoming message.")
-                self.delayedNotificationDispatch {
-                    Logger.info("\(self.logTag) dispatching")
-                    TSStorageManager.shared().newDatabaseConnection().read({ (transaction) in
+            OWSTableItem(title:"Last Incoming Message") { [weak self] in
+                guard let strongSelf = self else {
+                    return
+                }
+
+                Logger.info("\(strongSelf.logTag) scheduling notification for incoming message.")
+                strongSelf.delayedNotificationDispatch {
+                    Logger.info("\(strongSelf.logTag) dispatching")
+                    TSStorageManager.shared().newDatabaseConnection().read { (transaction) in
                         guard let viewTransaction = transaction.ext(TSMessageDatabaseViewExtensionName) as? YapDatabaseViewTransaction  else {
                             owsFail("unable to build view transaction")
                             return
@@ -55,28 +59,40 @@ class DebugUINotifications: DebugUIPage {
                             owsFail("last message was not an incoming message.")
                             return
                         }
-                        Logger.info("\(self.logTag) notifying user of incoming message")
-                        self.notificationsManager.notifyUser(for: incomingMessage, in: thread, contactsManager: self.contactsManager, transaction: transaction)
-                    })
+                        Logger.info("\(strongSelf.logTag) notifying user of incoming message")
+                        strongSelf.notificationsManager.notifyUser(for: incomingMessage, in: thread, contactsManager: strongSelf.contactsManager, transaction: transaction)
+                    }
                 }
             }
         ]
 
         if let contactThread = thread as? TSContactThread {
             sectionItems += [
-                OWSTableItem(title:"Call Missed") {
-                    self.delayedNotificationDispatchWithFakeCall(thread: contactThread) { call in
-                        self.notificationsAdapter.presentMissedCall(call, callerName: thread.name())
+                OWSTableItem(title:"Call Missed") { [weak self] in
+                    guard let strongSelf = self else {
+                        return
+                    }
+
+                    strongSelf.delayedNotificationDispatchWithFakeCall(thread: contactThread) { call in
+                        strongSelf.notificationsAdapter.presentMissedCall(call, callerName: thread.name())
                     }
                 },
-                OWSTableItem(title:"Call Rejected: New Safety Number") {
-                    self.delayedNotificationDispatchWithFakeCall(thread: contactThread) { call in
-                        self.notificationsAdapter.presentMissedCallBecauseOfNewIdentity(call: call, callerName: thread.name())
+                OWSTableItem(title:"Call Rejected: New Safety Number") { [weak self] in
+                    guard let strongSelf = self else {
+                        return
+                    }
+
+                    strongSelf.delayedNotificationDispatchWithFakeCall(thread: contactThread) { call in
+                        strongSelf.notificationsAdapter.presentMissedCallBecauseOfNewIdentity(call: call, callerName: thread.name())
                     }
                 },
-                OWSTableItem(title:"Call Rejected: No Longer Verified") {
-                    self.delayedNotificationDispatchWithFakeCall(thread: contactThread) { call in
-                        self.notificationsAdapter.presentMissedCallBecauseOfNoLongerVerifiedIdentity(call: call, callerName: thread.name())
+                OWSTableItem(title:"Call Rejected: No Longer Verified") { [weak self] in
+                    guard let strongSelf = self else {
+                        return
+                    }
+
+                    strongSelf.delayedNotificationDispatchWithFakeCall(thread: contactThread) { call in
+                        strongSelf.notificationsAdapter.presentMissedCallBecauseOfNoLongerVerifiedIdentity(call: call, callerName: thread.name())
                     }
                 }
             ]
diff --git a/SignalMessaging/utils/DisplayableText.swift b/SignalMessaging/utils/DisplayableText.swift
index cdfc21bbb..b8a888581 100644
--- a/SignalMessaging/utils/DisplayableText.swift
+++ b/SignalMessaging/utils/DisplayableText.swift
@@ -221,8 +221,11 @@ extension String {
             return nil
         }
 
-        // Notifications strip anything that looks lik a printf formatting character,
-        // so literal "%" must be escaped in order to appear in notification text.
+        // iOS strips anything that looks like a printf formatting character from
+        // the notification body, so if we want to dispay a literal "%" in a notification
+        // it must be escaped.
+        // see https://developer.apple.com/documentation/uikit/uilocalnotification/1616646-alertbody
+        // for more details.
         return text.replacingOccurrences(of: "%", with: "%%")
     }