diff --git a/src/main/java/de/ids_mannheim/korap/rewrite/CollectionCleanRewrite.java b/src/main/java/de/ids_mannheim/korap/rewrite/CollectionCleanRewrite.java
index f827871..5aacdd5 100644
--- a/src/main/java/de/ids_mannheim/korap/rewrite/CollectionCleanRewrite.java
+++ b/src/main/java/de/ids_mannheim/korap/rewrite/CollectionCleanRewrite.java
@@ -1,5 +1,6 @@
 package de.ids_mannheim.korap.rewrite;
 
+import java.util.Arrays;
 import java.util.Iterator;
 
 import com.fasterxml.jackson.databind.JsonNode;
@@ -7,7 +8,6 @@
 
 import de.ids_mannheim.korap.config.KustvaktConfiguration;
 import de.ids_mannheim.korap.user.User;
-import edu.emory.mathcs.backport.java.util.Arrays;
 
 /**
  * EM: not used anymore. This rewrite was to remove an empty koral:doc
diff --git a/src/main/java/de/ids_mannheim/korap/utils/KoralCollectionQueryBuilder.java b/src/main/java/de/ids_mannheim/korap/utils/KoralCollectionQueryBuilder.java
index 7dd99ad..28e75e9 100644
--- a/src/main/java/de/ids_mannheim/korap/utils/KoralCollectionQueryBuilder.java
+++ b/src/main/java/de/ids_mannheim/korap/utils/KoralCollectionQueryBuilder.java
@@ -1,5 +1,6 @@
 package de.ids_mannheim.korap.utils;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -12,7 +13,6 @@
 import de.ids_mannheim.korap.exceptions.StatusCodes;
 import de.ids_mannheim.korap.query.serialize.CollectionQueryProcessor;
 import de.ids_mannheim.korap.response.Notifications;
-import edu.emory.mathcs.backport.java.util.Arrays;
 
 /**
  * convenience builder class for collection query
diff --git a/src/test/java/de/ids_mannheim/korap/dao/UserGroupDaoTest.java b/src/test/java/de/ids_mannheim/korap/dao/UserGroupDaoTest.java
index 1ee65bf..c698321 100644
--- a/src/test/java/de/ids_mannheim/korap/dao/UserGroupDaoTest.java
+++ b/src/test/java/de/ids_mannheim/korap/dao/UserGroupDaoTest.java
@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -28,7 +29,6 @@
 import de.ids_mannheim.korap.exceptions.KustvaktException;
 import de.ids_mannheim.korap.exceptions.StatusCodes;
 import de.ids_mannheim.korap.user.User.CorpusAccess;
-import edu.emory.mathcs.backport.java.util.Collections;
 
 @ExtendWith(SpringExtension.class)
 @ContextConfiguration("classpath:test-config.xml")
diff --git a/src/test/java/de/ids_mannheim/korap/misc/MapUtilsTest.java b/src/test/java/de/ids_mannheim/korap/misc/MapUtilsTest.java
index 4d59790..bf389db 100644
--- a/src/test/java/de/ids_mannheim/korap/misc/MapUtilsTest.java
+++ b/src/test/java/de/ids_mannheim/korap/misc/MapUtilsTest.java
@@ -2,11 +2,12 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import java.util.Arrays;
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
+
 import de.ids_mannheim.korap.web.utils.MapUtils;
-import edu.emory.mathcs.backport.java.util.Arrays;
 import jakarta.ws.rs.core.MultivaluedHashMap;
 import jakarta.ws.rs.core.MultivaluedMap;
 
diff --git a/src/test/java/de/ids_mannheim/korap/user/UserdataTest.java b/src/test/java/de/ids_mannheim/korap/user/UserdataTest.java
index 0e99a7f..499208f 100644
--- a/src/test/java/de/ids_mannheim/korap/user/UserdataTest.java
+++ b/src/test/java/de/ids_mannheim/korap/user/UserdataTest.java
@@ -3,21 +3,22 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
+
 import com.fasterxml.jackson.databind.node.ArrayNode;
+
 import de.ids_mannheim.korap.config.Attributes;
 import de.ids_mannheim.korap.exceptions.KustvaktException;
 import de.ids_mannheim.korap.utils.JsonUtils;
 import de.ids_mannheim.korap.validator.ApacheValidator;
-import edu.emory.mathcs.backport.java.util.Arrays;
-
-import static org.junit.jupiter.api.Assertions.assertThrows;
 
 /**
  * @author hanl, margaretha