diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8705701..fa17b28 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## [1.4.0](https://github.com/christianrowlands/network-survey-messaging/releases/tag/v1.4.0) - 2024-08-08
+* Adds the slot field to the phone state record. See the docs for more information on the slot field.
+* Upgrade to the latest protobuf (4.27.3) and gRPC (1.65.1) library versions.
+
 ## [1.3.0](https://github.com/christianrowlands/network-survey-messaging/releases/tag/v1.3.0) - 2024-08-05
 * Adds the appVersion field to the device status message.
 
diff --git a/build.gradle b/build.gradle
index b206168..c7495fb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -24,7 +24,7 @@ version "1.3.0"
 
 // Configure the wrapper and ALL distro so IJ has additional context
 wrapper {
-    gradleVersion = '8.3'
+    gradleVersion = '8.9'
     distributionType = Wrapper.DistributionType.ALL
 }
 
@@ -33,8 +33,8 @@ repositories {
 }
 
 ext {
-    grpcVersion = '1.58.0'
-    protobufVersion = '3.24.3'
+    grpcVersion = '1.65.1'
+    protobufVersion = '4.27.3'
     protocVersion = protobufVersion
 
     sonatypeUsername = findCredentialValue('Username')
@@ -50,9 +50,9 @@ dependencies {
 
     implementation "javax.annotation:javax.annotation-api:1.3.2"
 
-    testImplementation "com.google.protobuf:protobuf-java-util:3.24.3"
-    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.10.0'
-    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.10.0'
+    testImplementation "com.google.protobuf:protobuf-java-util:$protobufVersion"
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.10.3'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.10.3'
 }
 
 test {
diff --git a/src/main/asyncapi/network_survey_messaging.yaml b/src/main/asyncapi/network_survey_messaging.yaml
index b958103..89d122b 100644
--- a/src/main/asyncapi/network_survey_messaging.yaml
+++ b/src/main/asyncapi/network_survey_messaging.yaml
@@ -1693,6 +1693,8 @@ components:
               $ref: '#/components/schemas/simState'
             simOperator:
               $ref: '#/components/schemas/simOperator'
+            slot:
+              $ref: '#/components/schemas/slot'
             networkRegistrationInfo:
               type: array
               items:
diff --git a/src/main/proto/com/craxiom/messaging/phone_state.proto b/src/main/proto/com/craxiom/messaging/phone_state.proto
index 430a7d3..561666c 100644
--- a/src/main/proto/com/craxiom/messaging/phone_state.proto
+++ b/src/main/proto/com/craxiom/messaging/phone_state.proto
@@ -45,6 +45,7 @@ message PhoneStateData {
     string simOperator = 10;
     repeated NetworkRegistrationInfo networkRegistrationInfo = 11;
     int32 accuracy = 12;
+    google.protobuf.Int32Value slot = 13;
 }
 
 // Used to report the details of a registered network