diff --git a/app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java b/app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java
index 88ac3808c..aaf96bd9b 100644
--- a/app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java
+++ b/app/src/main/java/org/schabi/newpipe/fragments/list/search/SearchFragment.java
@@ -906,8 +906,8 @@ public class SearchFragment extends BaseListFragment<SearchInfo, ListExtractor.I
     //////////////////////////////////////////////////////////////////////////*/
 
     @Override
-    public void selectedFilters(final List<FilterItem> theSelectedContentFilter,
-                                final List<FilterItem> theSelectedSortFilter) {
+    public void selectedFilters(@NonNull final List<FilterItem> theSelectedContentFilter,
+                                @NonNull final List<FilterItem> theSelectedSortFilter) {
 
         selectedContentFilter = theSelectedContentFilter;
         selectedSortFilter = theSelectedSortFilter;
diff --git a/app/src/main/java/org/schabi/newpipe/util/ServiceHelper.java b/app/src/main/java/org/schabi/newpipe/util/ServiceHelper.java
index 51f0c10eb..e48b7a721 100644
--- a/app/src/main/java/org/schabi/newpipe/util/ServiceHelper.java
+++ b/app/src/main/java/org/schabi/newpipe/util/ServiceHelper.java
@@ -17,6 +17,7 @@ import org.schabi.newpipe.extractor.services.peertube.PeertubeInstance;
 
 import java.util.EnumMap;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
@@ -324,10 +325,11 @@ public final class ServiceHelper {
         }
     }
 
-    public static String getTranslatedFilterString(final LibraryStringIds stringId,
-                                                   final Context context) {
+    public static String getTranslatedFilterString(@NonNull final LibraryStringIds stringId,
+                                                   @NonNull final Context context) {
         if (LIBRARY_STRING_ID_TO_RES_ID_MAP.containsKey(stringId)) {
-            return context.getString(LIBRARY_STRING_ID_TO_RES_ID_MAP.get(stringId));
+            return context.getString(
+                    Objects.requireNonNull(LIBRARY_STRING_ID_TO_RES_ID_MAP.get(stringId)));
         } else {
             return stringId.toString();
         }