diff --git a/app/build.gradle b/app/build.gradle
index f348d2a..5862f39 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -4,14 +4,15 @@ apply plugin: 'kotlin-android-extensions'
 
 android {
     // Note: SDK version 31 includes a great many revisions to core platform APIs.
-    compileSdkVersion 30
+    compileSdkVersion 34
 
     defaultConfig {
         applicationId "com.danefinlay.ttsutil"
         minSdkVersion 15
-        targetSdkVersion 30
+        targetSdkVersion 34
         versionCode 8
         versionName "4.0.2"
+        multiDexEnabled true
     }
 
     lintOptions {
@@ -45,23 +46,25 @@ dependencies {
     implementation 'androidx.documentfile:documentfile:1.0.1'
     implementation 'androidx.navigation:navigation-fragment-ktx:2.0.0'
     implementation 'androidx.navigation:navigation-ui-ktx:2.0.0'
-    implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
     implementation 'androidx.navigation:navigation-fragment-ktx:2.0.0'
     implementation 'androidx.navigation:navigation-ui-ktx:2.0.0'
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    implementation 'androidx.appcompat:appcompat:1.0.2'
+    implementation 'androidx.appcompat:appcompat:1.6.1'
     implementation 'androidx.preference:preference-ktx:1.0.0'
     implementation 'org.jetbrains.anko:anko-sdk15:0.9'
     implementation 'org.jetbrains.anko:anko-support-v4:0.9.1'
-    implementation 'androidx.constraintlayout:constraintlayout:2.0.0'
-    implementation 'com.google.android.material:material:1.0.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+    implementation 'com.google.android.material:material:1.9.0'
+
+    implementation 'com.android.support:multidex:1.0.0'
 }
+
 repositories {
     mavenCentral()
     google()
 }
 
-
 task wrapper(type: Wrapper) {
     gradleVersion = '2.0'
 }
diff --git a/app/src/main/java/com/danefinlay/ttsutil/ui/ActivityEvents.kt b/app/src/main/java/com/danefinlay/ttsutil/ui/ActivityEvents.kt
index 48a69d3..607d187 100644
--- a/app/src/main/java/com/danefinlay/ttsutil/ui/ActivityEvents.kt
+++ b/app/src/main/java/com/danefinlay/ttsutil/ui/ActivityEvents.kt
@@ -58,7 +58,7 @@ sealed class ActivityEvent : Parcelable {
     }
 
     class TTSReadyEvent : ActivityEvent(), Parcelable {
-        override fun writeToParcel(dest: Parcel?, flags: Int) {}
+        override fun writeToParcel(p0: Parcel, flags: Int) {}
         override fun describeContents(): Int = 0
 
         companion object CREATOR : Parcelable.Creator<TTSReadyEvent> {
diff --git a/app/src/main/java/com/danefinlay/ttsutil/ui/ReadTextFragments.kt b/app/src/main/java/com/danefinlay/ttsutil/ui/ReadTextFragments.kt
index fe2c742..b65cd56 100644
--- a/app/src/main/java/com/danefinlay/ttsutil/ui/ReadTextFragments.kt
+++ b/app/src/main/java/com/danefinlay/ttsutil/ui/ReadTextFragments.kt
@@ -263,7 +263,7 @@ abstract class ReadTextFragmentBase : MyFragment() {
     override fun onClickSave() {
         super.onClickSave()
 
-        // Determine the output directory.  If the user has not chosen one, the
+        // Determine the output directory. If the user has not chosen one, the
         // "external" storage is used.
         val event = activityInterface?.getLastDirChosenEvent()
         val directory: Directory = if (event != null) {
@@ -274,16 +274,21 @@ abstract class ReadTextFragmentBase : MyFragment() {
         }
 
         // Determine the names of the wave file and directory.
-        // TODO Allow the user to change the filename.
-        val waveFilename = getString(R.string.output_wave_filename) + ".wav"
+        // Get the current date and time in the format 'ddMMyyyy_HHmmss'.
+        val currentDateTime = SimpleDateFormat("ddMMyyyy_HHmmss", Locale.getDefault()).format(Date())
+
+        // Append the current date and time to the filename.
+        val waveFilename = "textToSpeech_$currentDateTime.wav"
+
         val dirDisplayName: String = event?.firstDisplayName
-                ?: getString(R.string.default_output_dir)
+            ?: getString(R.string.default_output_dir)
 
         // Build and display an appropriate alert dialog.
         AlertDialogBuilder(ctx).apply {
             title(R.string.write_to_file_alert_title)
-            message(getString(R.string.write_to_file_alert_message_3,
-                    waveFilename, dirDisplayName))
+            message(getString(
+                R.string.write_to_file_alert_message_3,
+                waveFilename, dirDisplayName))
             positiveButton(R.string.alert_positive_message_2) {
                 // Ask the user for write permission if necessary.
                 withStoragePermission { granted ->
diff --git a/build.gradle b/build.gradle
index b1045eb..7051e60 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,8 +7,8 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.0.4'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.20"
+        classpath 'com.android.tools.build:gradle:7.4.2'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.0"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index b38c35a..b51c614 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-bin.zip