diff --git a/app/src/main/java/eu/faircode/email/ApplicationEx.java b/app/src/main/java/eu/faircode/email/ApplicationEx.java
index c4b895a7e7..3b2a5bb165 100644
--- a/app/src/main/java/eu/faircode/email/ApplicationEx.java
+++ b/app/src/main/java/eu/faircode/email/ApplicationEx.java
@@ -34,11 +34,10 @@ import android.os.strictmode.Violation;
 import android.util.Printer;
 import android.webkit.CookieManager;
 
+import androidx.annotation.NonNull;
 import androidx.preference.PreferenceManager;
 import androidx.work.WorkManager;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Locale;
@@ -132,7 +131,7 @@ public class ApplicationEx extends Application
 
         Thread.setDefaultUncaughtExceptionHandler(new Thread.UncaughtExceptionHandler() {
             @Override
-            public void uncaughtException(@NotNull Thread thread, @NotNull Throwable ex) {
+            public void uncaughtException(@NonNull Thread thread, @NonNull Throwable ex) {
                 if (!crash_reports && Log.isOwnFault(ex)) {
                     Log.e(ex);
 
diff --git a/app/src/main/java/eu/faircode/email/FragmentOptions.java b/app/src/main/java/eu/faircode/email/FragmentOptions.java
index bb3ee70207..02573cb276 100644
--- a/app/src/main/java/eu/faircode/email/FragmentOptions.java
+++ b/app/src/main/java/eu/faircode/email/FragmentOptions.java
@@ -61,8 +61,6 @@ import androidx.viewpager.widget.ViewPager;
 
 import com.google.android.material.tabs.TabLayout;
 
-import org.jetbrains.annotations.NotNull;
-
 public class FragmentOptions extends FragmentBase {
     private ViewPager pager;
     private PagerAdapter adapter;
@@ -408,7 +406,7 @@ public class FragmentOptions extends FragmentBase {
             return 10;
         }
 
-        @NotNull
+        @NonNull
         @Override
         public Fragment getItem(int position) {
             switch (position) {
@@ -448,7 +446,7 @@ public class FragmentOptions extends FragmentBase {
             return ssb;
         }
 
-        @NotNull
+        @NonNull
         private CharSequence getTitle(int position) {
             switch (position) {
                 case 0:
diff --git a/app/src/main/java/eu/faircode/email/MessageClassifier.java b/app/src/main/java/eu/faircode/email/MessageClassifier.java
index 5fbda0cb13..4177056a8e 100644
--- a/app/src/main/java/eu/faircode/email/MessageClassifier.java
+++ b/app/src/main/java/eu/faircode/email/MessageClassifier.java
@@ -30,8 +30,6 @@ import android.util.MalformedJsonException;
 import androidx.annotation.NonNull;
 import androidx.preference.PreferenceManager;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
 import java.io.File;
@@ -735,7 +733,7 @@ public class MessageClassifier {
             this.chance = chance;
         }
 
-        @NotNull
+        @NonNull
         @Override
         public String toString() {
             return clazz + "=" + Math.round(chance * 100.0 * 100.0) / 100.0 + "%";