diff --git a/app/build.gradle b/app/build.gradle
index 80e5d9245..2eaee1631 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -227,6 +227,10 @@ dependencies {
     implementation "com.google.android.gms:play-services-ads:$rootProject.ext.playServicesAdsVersion"
     implementation "com.google.android.ump:user-messaging-platform:$rootProject.ext.userMessagingPlatformVersion"
 
+    // Liftoff Monetize mediation via AdMob
+    implementation "com.google.ads.mediation:vungle:$rootProject.ext.liftoffMediationAdapterVersion"
+    implementation "com.vungle:vungle-ads:$rootProject.ext.vungleAdsVersion"
+
     // Play In-App Updates
     implementation "com.google.android.play:app-update:$rootProject.ext.playAppUpdateVersion"
 
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index af2465ba7..89d181383 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,7 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:installLocation="auto">
 
-    <uses-sdk tools:overrideLibrary="ca.psiphon,com.google.android.gms.ads.impl,com.google.android.gms.ads"/>
+    <uses-sdk tools:overrideLibrary="ca.psiphon,com.google.android.gms.ads.impl,com.google.android.gms.ads,com.vungle.mediation,com.google.android.ads.consent,com.google.android.gms.common"/>
     <supports-screens
                   android:smallScreens="true"
                   android:normalScreens="true"
diff --git a/app/src/main/java/com/psiphon3/ads/ConsentManager.kt b/app/src/main/java/com/psiphon3/ads/ConsentManager.kt
index 13a525f3a..b75189afa 100644
--- a/app/src/main/java/com/psiphon3/ads/ConsentManager.kt
+++ b/app/src/main/java/com/psiphon3/ads/ConsentManager.kt
@@ -21,6 +21,7 @@ package com.psiphon3.ads
 
 import android.app.Activity
 import android.content.Context
+import android.os.Build
 import com.google.android.ump.ConsentInformation
 import com.google.android.ump.ConsentRequestParameters
 import com.google.android.ump.UserMessagingPlatform
@@ -41,9 +42,15 @@ class ConsentManager private constructor(context: Context) {
         }
     }
 
-    private val consentInformation = UserMessagingPlatform.getConsentInformation(context)
+    // UMP requires API >= 23; on pre-M this is null and all methods become no-ops.
+    private val consentInformation: ConsentInformation? =
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M)
+            UserMessagingPlatform.getConsentInformation(context)
+        else null
 
     fun gatherConsent(activity: Activity): Completable {
+        val info = consentInformation ?: return Completable.complete()
+
         return Completable.create { emitter ->
             if (activity.isFinishing || activity.isDestroyed) {
                 if (!emitter.isDisposed) {
@@ -57,7 +64,7 @@ class ConsentManager private constructor(context: Context) {
             val params = ConsentRequestParameters.Builder()
                 .build()
 
-            consentInformation.requestConsentInfoUpdate(
+            info.requestConsentInfoUpdate(
                 activity,
                 params,
                 {
@@ -92,6 +99,8 @@ class ConsentManager private constructor(context: Context) {
     }
 
     fun showPrivacyOptionsForm(activity: Activity): Completable {
+        consentInformation ?: return Completable.complete()
+
         return Completable.create { emitter ->
             if (activity.isFinishing || activity.isDestroyed) {
                 if (!emitter.isDisposed) {
@@ -114,10 +123,10 @@ class ConsentManager private constructor(context: Context) {
         }
     }
 
-    fun canRequestAds(): Boolean = consentInformation.canRequestAds()
+    fun canRequestAds(): Boolean = consentInformation?.canRequestAds() ?: false
 
     fun isPrivacyOptionsRequired(): Boolean {
-        return consentInformation.privacyOptionsRequirementStatus ==
+        return consentInformation?.privacyOptionsRequirementStatus ==
                 ConsentInformation.PrivacyOptionsRequirementStatus.REQUIRED
     }
-}
\ No newline at end of file
+}
diff --git a/build.gradle b/build.gradle
index 463257878..fb1db9dd4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -52,8 +52,10 @@ ext {
     pagingVersion = '2.1.2'
     locationServicesVersion = '21.0.1'
     geoHashVersion = '0.22'
-    playServicesAdsVersion = '24.6.0'
-    userMessagingPlatformVersion = '3.1.0'
+    playServicesAdsVersion = '24.9.0'
+    userMessagingPlatformVersion = '4.0.0'
+    liftoffMediationAdapterVersion = '7.7.0.1'
+    vungleAdsVersion = '7.7.0'
     coreKtxVersion = '1.16.0'
     playAppUpdateVersion = '2.1.0'
 }