diff --git a/AWSComprehendTests/AWSComprehendTests.swift b/AWSComprehendTests/AWSComprehendTests.swift
index 235459cfb26..83d57f30e47 100644
--- a/AWSComprehendTests/AWSComprehendTests.swift
+++ b/AWSComprehendTests/AWSComprehendTests.swift
@@ -139,7 +139,7 @@ class AWSComprehendTests: XCTestCase {
         let comprehendClient = AWSComprehend.default()
         let detectSentimentRequest = AWSComprehendDetectSentimentRequest()
         detectSentimentRequest!.languageCode = AWSComprehendLanguageCode.en
-        detectSentimentRequest!.text = "I have no strong feelings one way or the other"
+        detectSentimentRequest!.text = "This sentence is a statement of fact"
         
         comprehendClient.detectSentiment(detectSentimentRequest!).continueWith{ (task)-> Any? in
             if let error = task.error {
diff --git a/AWSIoT/Internal/AWSIoTMQTTClient.m b/AWSIoT/Internal/AWSIoTMQTTClient.m
index 5e51604c4a9..1650db6f147 100644
--- a/AWSIoT/Internal/AWSIoTMQTTClient.m
+++ b/AWSIoT/Internal/AWSIoTMQTTClient.m
@@ -38,7 +38,7 @@ @interface AWSIoTMQTTClient() <AWSSRWebSocketDelegate, NSStreamDelegate, AWSMQTT
 
 @property(atomic, assign, readwrite) AWSIoTMQTTStatus mqttStatus;
 @property(nonatomic, strong) AWSMQTTSession* session;
-@property(nonatomic, strong) NSMutableDictionary * topicListeners;
+@property(nonatomic, strong) AWSSynchronizedMutableDictionary * topicListeners;
 
 @property(atomic, assign) BOOL userDidIssueDisconnect; //Flag to indicate if requestor has issued a disconnect
 @property(atomic, assign) BOOL userDidIssueConnect; //Flag to indicate if requestor has issued a connect
@@ -91,7 +91,7 @@ @implementation AWSIoTMQTTClient
 
 - (instancetype)init {
     if (self = [super init]) {
-        _topicListeners = [NSMutableDictionary dictionary];
+        _topicListeners = [AWSSynchronizedMutableDictionary new];
         _clientCerts = nil;
         _session.delegate = nil;
         _session = nil;
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4fdfa57a49f..48cd7f33e2b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,19 @@
 # AWS Mobile SDK for iOS CHANGELOG
 
+## Unreleased
+
+### Bug Fixes
+
+- **AWSIoT** 
+  - Fixing a potential race condition on topic listeners (#5402)
+
+## 2.36.5
+
+### New features 
+
+- **AWSIoT** 
+  - Adding completion callbacks for registerWithShadow and unregisterFromShadow methods (#5192)
+
 ### Misc. Updates
 
 - Model updates for the following services
@@ -16,11 +30,11 @@
   - AWSFirehose
   - AWSTranscribe
 
-- **AWSS3** 
-  - fix(s3): cleanup file cache after mpu task is cancelled (#5128)
- 
-- **AWSIOT** 
-  - feat(IoT): Adding completion callbacks for registerWithShadow and unregisterFromShadow methods (#5192)
+## 2.36.4
+
+### Deprecated release
+
+This release is deprecated due to errors. Please use 2.36.5 or greater.
 
 ## 2.36.3