diff --git a/uimaj-core/src/test/java/org/apache/uima/analysis_engine/impl/AnalysisEngine_implTest.java b/uimaj-core/src/test/java/org/apache/uima/analysis_engine/impl/AnalysisEngine_implTest.java
index 2529498da..9fddec776 100644
--- a/uimaj-core/src/test/java/org/apache/uima/analysis_engine/impl/AnalysisEngine_implTest.java
+++ b/uimaj-core/src/test/java/org/apache/uima/analysis_engine/impl/AnalysisEngine_implTest.java
@@ -104,9 +104,9 @@
 import org.apache.uima.util.XMLSerializer;
 import org.apache.uima.util.impl.ProcessTrace_impl;
 import org.assertj.core.api.AutoCloseableSoftAssertions;
-import org.custommonkey.xmlunit.XMLAssert;
 import org.junit.jupiter.api.Test;
 import org.xml.sax.ContentHandler;
+import org.xmlunit.assertj3.XmlAssert;
 
 /**
  * Tests the TextAnalysisEngine_impl class.
@@ -1729,7 +1729,7 @@ private void manyDelegatesCommon() throws Exception {
 
     String inXml = FileCompare.file2String(inFile);
     String cloneXml = FileCompare.file2String(cloneFile);
-    XMLAssert.assertXMLEqual(inXml, cloneXml);
+    XmlAssert.assertThat(cloneXml).and(inXml).areIdentical();
     // When building from a source distribution the descriptor may not have
     // appropriate line-ends so compute the length as if always 1 byte.
     int diff = fileLength(cloneFile) - fileLength(inFile);
diff --git a/uimaj-core/src/test/java/org/apache/uima/util/CasToInlineXmlTest.java b/uimaj-core/src/test/java/org/apache/uima/util/CasToInlineXmlTest.java
index ccf8dfa48..73e8a90d6 100644
--- a/uimaj-core/src/test/java/org/apache/uima/util/CasToInlineXmlTest.java
+++ b/uimaj-core/src/test/java/org/apache/uima/util/CasToInlineXmlTest.java
@@ -38,9 +38,8 @@
 import org.apache.uima.test.junit_extension.JUnitExtension;
 import org.apache.uima.testTypeSystem_arrays.OfShorts;
 import org.apache.uima.testTypeSystem_arrays.OfStrings;
-import org.custommonkey.xmlunit.XMLAssert;
-import org.custommonkey.xmlunit.XMLUnit;
 import org.junit.jupiter.api.Test;
+import org.xmlunit.assertj3.XmlAssert;
 
 public class CasToInlineXmlTest {
 
@@ -160,14 +159,8 @@ public void testCasToInlineXml() throws Exception {
         break;
       }
     }
-    boolean whitespaceFlag = XMLUnit.getIgnoreWhitespace();
-    XMLUnit.setIgnoreWhitespace(true);
-    try {
-      XMLAssert.assertXMLEqual(expected, result);
-    } finally {
-      XMLUnit.setIgnoreWhitespace(whitespaceFlag);
-    }
-    // assertEquals(expected, result.trim());
+
+    XmlAssert.assertThat(result).and(expected).ignoreWhitespace().areIdentical();
   }
 
   private String canonicalizeNl(String s) {
diff --git a/uimaj-json/src/test/java/org/apache/uima/json/JsonCasSerializerTest.java b/uimaj-json/src/test/java/org/apache/uima/json/JsonCasSerializerTest.java
index f22892c91..95bf4c475 100644
--- a/uimaj-json/src/test/java/org/apache/uima/json/JsonCasSerializerTest.java
+++ b/uimaj-json/src/test/java/org/apache/uima/json/JsonCasSerializerTest.java
@@ -57,10 +57,10 @@
 import org.apache.uima.util.XMLInputSource;
 import org.apache.uima.util.XMLParser;
 import org.apache.uima.util.XMLSerializer;
-import org.custommonkey.xmlunit.XMLAssert;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.xml.sax.SAXException;
+import org.xmlunit.assertj3.XmlAssert;
 
 public class JsonCasSerializerTest {
   // @formatter:off
@@ -584,7 +584,7 @@ private void compareWithExpected(String expectedResultsName, String r)
     if (doJson) {
       assertEquals(ce, r);
     } else {
-      XMLAssert.assertXMLEqual(ce, r);
+      XmlAssert.assertThat(r).and(ce).areIdentical();
     }
   }
 
diff --git a/uimaj-parent/pom.xml b/uimaj-parent/pom.xml
index 8ffe0425d..2331b13d8 100644
--- a/uimaj-parent/pom.xml
+++ b/uimaj-parent/pom.xml
@@ -141,6 +141,7 @@
     <jackson-version>2.13.1</jackson-version>
     <junit-version>5.8.2</junit-version>
     <assertj-version>3.22.0</assertj-version>
+    <xmlunit-version>2.9.0</xmlunit-version>
 
     <maven.compiler.target>1.8</maven.compiler.target>
     <maven.compiler.source>1.8</maven.compiler.source>
@@ -190,9 +191,14 @@
         <version>${slf4j-version}</version>
       </dependency>
       <dependency>
-        <groupId>xmlunit</groupId>
-        <artifactId>xmlunit</artifactId>
-        <version>1.6</version>
+        <groupId>org.xmlunit</groupId>
+        <artifactId>xmlunit-core</artifactId>
+        <version>${xmlunit-version}</version>
+      </dependency>
+      <dependency>
+        <groupId>org.xmlunit</groupId>
+        <artifactId>xmlunit-assertj3</artifactId>
+        <version>${xmlunit-version}</version>
       </dependency>
       <dependency>
         <groupId>${eclipseP2RepoId}</groupId>
diff --git a/uimaj-test-util/pom.xml b/uimaj-test-util/pom.xml
index 14bcb5e03..69c5c1b0a 100644
--- a/uimaj-test-util/pom.xml
+++ b/uimaj-test-util/pom.xml
@@ -51,8 +51,14 @@
       <scope>compile</scope>  <!-- is normally test scope, so need to be explicit -->
     </dependency>
     <dependency>
-      <groupId>xmlunit</groupId>
-      <artifactId>xmlunit</artifactId>
+      <groupId>org.xmlunit</groupId>
+      <artifactId>xmlunit-core</artifactId>
+      <version>${xmlunit-version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.xmlunit</groupId>
+      <artifactId>xmlunit-assertj3</artifactId>
+      <version>${xmlunit-version}</version>
     </dependency>
   </dependencies>
 </project>
\ No newline at end of file