diff --git a/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java b/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java
index 08daa0e17..470d8bc64 100644
--- a/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java
+++ b/src/tests/junit/org/apache/tools/ant/taskdefs/optional/junit/JUnitTaskTest.java
@@ -563,7 +563,8 @@ public class JUnitTaskTest {
 
         @Override
         public Process exec(Project project, String[] cmd, String[] env, File workingDir) throws IOException {
-            this.cmd = Arrays.copyOf(cmd, cmd.length);
+            this.cmd = new String[cmd.length];
+            System.arraycopy(cmd, 0, this.cmd, 0, cmd.length);
             return new MockProcess();
         }