diff --git a/build.gradle b/build.gradle
index 06c5f0030..c102d9e39 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:7.2.1'
+        classpath 'com.android.tools.build:gradle:7.2.2'
     }
 }
 
@@ -73,7 +73,7 @@ dependencies {
     implementation "com.squareup.retrofit2:converter-gson:2.9.0"
     implementation "com.squareup.okhttp3:okhttp:4.10.0"
 
-    implementation 'com.google.guava:guava:30.1.1-android'
+    implementation 'com.google.guava:guava:31.1-android'
     quicksyImplementation 'io.michaelrocks:libphonenumber-android:8.12.49'
     freeImplementation 'ch.threema:webrtc-android:100.0.0'
     playstoreImplementation fileTree(include: ['libwebrtc-m104.aar'], dir: 'libs')
diff --git a/src/main/java/eu/siacs/conversations/http/HttpUploadConnection.java b/src/main/java/eu/siacs/conversations/http/HttpUploadConnection.java
index 20db7bfbd..3e478dd0f 100644
--- a/src/main/java/eu/siacs/conversations/http/HttpUploadConnection.java
+++ b/src/main/java/eu/siacs/conversations/http/HttpUploadConnection.java
@@ -2,14 +2,14 @@ package eu.siacs.conversations.http;
 
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.MoreExecutors;
 
-import org.checkerframework.checker.nullness.compatqual.NullableDecl;
-import org.jetbrains.annotations.NotNull;
-
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
@@ -132,7 +132,7 @@ public class HttpUploadConnection implements Transferable, AbstractConnectionMan
         this.slotFuture = new SlotRequester(mXmppConnectionService).request(method, account, file, mime);
         Futures.addCallback(this.slotFuture, new FutureCallback<SlotRequester.Slot>() {
             @Override
-            public void onSuccess(@NullableDecl SlotRequester.Slot result) {
+            public void onSuccess(@Nullable SlotRequester.Slot result) {
                 HttpUploadConnection.this.slot = result;
                 try {
                     HttpUploadConnection.this.upload();
@@ -142,7 +142,7 @@ public class HttpUploadConnection implements Transferable, AbstractConnectionMan
             }
 
             @Override
-            public void onFailure(@NotNull final Throwable throwable) {
+            public void onFailure(@NonNull final Throwable throwable) {
                 Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": unable to request slot", throwable);
                 // TODO consider fall back to jingle in 1-on-1 chats with exactly one online presence
                 fail(throwable.getMessage());
@@ -169,13 +169,13 @@ public class HttpUploadConnection implements Transferable, AbstractConnectionMan
         this.mostRecentCall = client.newCall(request);
         this.mostRecentCall.enqueue(new Callback() {
             @Override
-            public void onFailure(@NotNull Call call, IOException e) {
+            public void onFailure(@NonNull Call call, IOException e) {
                 Log.d(Config.LOGTAG, "http upload failed", e);
                 fail(e.getMessage());
             }
 
             @Override
-            public void onResponse(@NotNull Call call, @NotNull Response response)  {
+            public void onResponse(@NonNull Call call, @NonNull Response response)  {
                 final int code = response.code();
                 if (code == 200 || code == 201) {
                     Log.d(Config.LOGTAG, "finished uploading file");
diff --git a/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java b/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
index fc7b50449..cbf00d04b 100644
--- a/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
@@ -25,6 +25,7 @@ import android.view.WindowManager;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.StringRes;
 import androidx.databinding.DataBindingUtil;
@@ -37,7 +38,6 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.util.concurrent.FutureCallback;
 import com.google.common.util.concurrent.Futures;
 
-import org.checkerframework.checker.nullness.compatqual.NullableDecl;
 import org.webrtc.RendererCommon;
 import org.webrtc.SurfaceViewRenderer;
 import org.webrtc.VideoTrack;
@@ -999,7 +999,7 @@ public class RtpSessionActivity extends XmppActivity
                 requireRtpConnection().switchCamera(),
                 new FutureCallback<Boolean>() {
                     @Override
-                    public void onSuccess(@NullableDecl Boolean isFrontCamera) {
+                    public void onSuccess(@Nullable Boolean isFrontCamera) {
                         binding.localVideo.setMirror(isFrontCamera);
                     }
 
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpContentMap.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpContentMap.java
index e7693d6a8..bba44f963 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpContentMap.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/RtpContentMap.java
@@ -1,6 +1,5 @@
 package eu.siacs.conversations.xmpp.jingle;
 
-import com.google.common.base.Function;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
 import com.google.common.collect.Collections2;
@@ -11,8 +10,6 @@ import com.google.common.collect.Iterables;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 
-import org.checkerframework.checker.nullness.compatqual.NullableDecl;
-
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -292,13 +289,7 @@ public class RtpContentMap {
             return ImmutableMap.copyOf(
                     Maps.transformValues(
                             contents,
-                            new Function<Content, DescriptionTransport>() {
-                                @NullableDecl
-                                @Override
-                                public DescriptionTransport apply(@NullableDecl Content content) {
-                                    return content == null ? null : of(content);
-                                }
-                            }));
+                            content -> content == null ? null : of(content)));
         }
     }