diff --git a/.idea/misc.xml b/.idea/misc.xml
index c696fb6..30a5bdc 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -4,6 +4,7 @@
     <pattern value="rife.bld.extension.TestNgOperationBuild" method="pmd" />
     <pattern value="rife.bld.extension.TestNgOperationBuild" />
     <pattern value="rife.bld.extension.TestNGSimpleTest" method="testFail" />
+    <pattern value="rife.bld.extension.TestNgSimpleTest" method="testFail" />
   </component>
   <component name="PDMPlugin">
     <option name="customRuleSets">
diff --git a/src/bld/java/rife/bld/extension/TestNgOperationBuild.java b/src/bld/java/rife/bld/extension/TestNgOperationBuild.java
index 890d916..ed53d3c 100644
--- a/src/bld/java/rife/bld/extension/TestNgOperationBuild.java
+++ b/src/bld/java/rife/bld/extension/TestNgOperationBuild.java
@@ -26,7 +26,8 @@ import java.util.List;
 
 import static rife.bld.dependencies.Repository.MAVEN_CENTRAL;
 import static rife.bld.dependencies.Repository.RIFE2_RELEASES;
-import static rife.bld.dependencies.Scope.*;
+import static rife.bld.dependencies.Scope.compile;
+import static rife.bld.dependencies.Scope.test;
 import static rife.bld.operations.JavadocOptions.DocLinkOption.NO_MISSING;
 
 public class TestNgOperationBuild extends Project {
diff --git a/src/main/java/rife/bld/extension/TestNgOperation.java b/src/main/java/rife/bld/extension/TestNgOperation.java
index c2e6f0f..b4dc366 100644
--- a/src/main/java/rife/bld/extension/TestNgOperation.java
+++ b/src/main/java/rife/bld/extension/TestNgOperation.java
@@ -52,6 +52,10 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
      * The suites to run.
      */
     protected final List<String> suites = new ArrayList<>();
+    /**
+     * The classpath entries used for running tests.
+     */
+    protected final List<String> testClasspath = new ArrayList<>();
     private final List<String> args = new ArrayList<>();
     private BaseProject project;
 
@@ -118,9 +122,15 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
 
         args.clear();
         args.add(javaTool());
+
         args.add("-cp");
-        args.add(String.format("%s:%s:%s", Path.of(project.libTestDirectory().getPath(), "*"),
-                project.buildMainDirectory(), project.buildTestDirectory()));
+        if (testClasspath.isEmpty()) {
+            args.add(String.format("%s:%s:%s", Path.of(project.libTestDirectory().getPath(), "*"),
+                    project.buildMainDirectory(), project.buildTestDirectory()));
+        } else {
+            args.add(String.join(":", testClasspath));
+        }
+
         args.add("org.testng.TestNG");
 
         options.forEach((k, v) -> {
@@ -406,6 +416,14 @@ public class TestNgOperation extends AbstractProcessOperation<TestNgOperation> {
         return this;
     }
 
+    /**
+     * Specifies the classpath entries used to run tests.
+     */
+    public TestNgOperation testClasspath(String... entry) {
+        testClasspath.addAll(Arrays.stream(entry).toList());
+        return this;
+    }
+
     /**
      * Specifies a jar file that contains test classes. If a {@code testng.xml} file is found at the root of that
      * jar file, it will be used, otherwise, all the test classes found in this jar file will be considered test
diff --git a/src/test/java/rife/bld/extension/TestNgOperationTest.java b/src/test/java/rife/bld/extension/TestNgOperationTest.java
index 3fec70b..bf61aaa 100644
--- a/src/test/java/rife/bld/extension/TestNgOperationTest.java
+++ b/src/test/java/rife/bld/extension/TestNgOperationTest.java
@@ -77,32 +77,42 @@ class TestNgOperationTest {
         assertThatThrownBy(() ->
                 new TestNgOperation().fromProject(new Project())
                         .testClass("rife.bld.extension.TestNgSimpleTest")
-                        .execute()).isInstanceOf(ExitStatusException.class);
+                        .execute())
+                .as("with testClass").isInstanceOf(ExitStatusException.class);
 
         assertThatThrownBy(() ->
                 new TestNgOperation().fromProject(new Project())
                         .suites("src/test/resources/testng.xml")
-                        .execute()).isInstanceOf(ExitStatusException.class);
+                        .execute())
+                .as("with suites").isInstanceOf(ExitStatusException.class);
 
         assertThatCode(() ->
                 new TestNgOperation().fromProject(new Project())
                         .testClass("rife.bld.extension.TestNgSimpleTest")
                         .methods("rife.bld.extension.TestNgSimpleTest.verifyHello")
                         .execute())
-                .doesNotThrowAnyException();
+                .as("with methods").doesNotThrowAnyException();
 
         assertThatCode(() ->
                 new TestNgOperation().fromProject(new Project())
                         .suites("src/test/resources/testng2.xml")
                         .execute())
-                .doesNotThrowAnyException();
+                .as("suite 2").doesNotThrowAnyException();
 
         assertThatCode(() ->
                 new TestNgOperation().fromProject(new Project())
                         .suites("src/test/resources/testng3.xml")
                         .log(2)
                         .execute())
-                .doesNotThrowAnyException();
+                .as("suite 3").doesNotThrowAnyException();
+
+        assertThatCode(() ->
+                new TestNgOperation().fromProject(new Project())
+                        .suites("src/test/resources/testng3.xml")
+                        .testClasspath("lib/test/*", "build/main", "build/test")
+                        .log(2)
+                        .execute())
+                .as("with run classpath").doesNotThrowAnyException();
     }
 
     @Test
diff --git a/src/test/java/rife/bld/extension/TestNgSimpleTest.java b/src/test/java/rife/bld/extension/TestNgSimpleTest.java
index 59f472d..6c091ec 100644
--- a/src/test/java/rife/bld/extension/TestNgSimpleTest.java
+++ b/src/test/java/rife/bld/extension/TestNgSimpleTest.java
@@ -30,13 +30,13 @@ class TestNgSimpleTest {
         new TestNgSimpleTest().verifyHello();
     }
 
-    @Test
-    void verifyHello() {
-        Assert.assertTrue(true);
-    }
-
     @Test
     void testFail() {
         Assert.fail("failed");
     }
+
+    @Test
+    void verifyHello() {
+        Assert.assertTrue(true);
+    }
 }
diff --git a/src/test/resources/testng.xml b/src/test/resources/testng.xml
index 0924379..41fd8ae 100644
--- a/src/test/resources/testng.xml
+++ b/src/test/resources/testng.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<suite name="test suite 1" verbose="2" >
-  <test name="simple test" >
-  <classes>
-      <class name="rife.bld.extension.TestNgSimpleTest" />
-   </classes>
- </test>
+<suite name="test suite 1" verbose="2">
+    <test name="simple test">
+        <classes>
+            <class name="rife.bld.extension.TestNgSimpleTest"/>
+        </classes>
+    </test>
 </suite>
\ No newline at end of file
diff --git a/src/test/resources/testng2.xml b/src/test/resources/testng2.xml
index 51b74ef..01168b7 100644
--- a/src/test/resources/testng2.xml
+++ b/src/test/resources/testng2.xml
@@ -1,10 +1,10 @@
 <!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >
-<suite name="test suite 2" verbose="1" >
-    <test name="exclude fail" >
+<suite name="test suite 2" verbose="1">
+    <test name="exclude fail">
         <classes>
             <class name="rife.bld.extension.TestNgSimpleTest">
                 <methods>
-                    <exclude name="testFail" />
+                    <exclude name="testFail"/>
                 </methods>
             </class>
         </classes>
diff --git a/src/test/resources/testng3.xml b/src/test/resources/testng3.xml
index bb9772f..baa78e5 100644
--- a/src/test/resources/testng3.xml
+++ b/src/test/resources/testng3.xml
@@ -1,10 +1,10 @@
 <!DOCTYPE suite SYSTEM "https://testng.org/testng-1.0.dtd" >
-<suite name="test suite 3" >
-    <test name="test 2 classes" >
+<suite name="test suite 3">
+    <test name="test 2 classes">
         <classes>
             <class name="rife.bld.extension.TestNgSimpleTest">
                 <methods>
-                    <exclude name="testFail" />
+                    <exclude name="testFail"/>
                 </methods>
             </class>
             <class name="rife.bld.extension.TestNgSimple2Test"/>