diff --git a/src/test/java/net/openhft/chronicle/map/MarkTest.java b/src/test/java/net/openhft/chronicle/map/MarkTest.java
index 504e5df69..03ef0b534 100644
--- a/src/test/java/net/openhft/chronicle/map/MarkTest.java
+++ b/src/test/java/net/openhft/chronicle/map/MarkTest.java
@@ -46,7 +46,8 @@ public class MarkTest {
 
     @Test(timeout = 25000)
     public void persistedTest() {
-        final File db = Paths.get(System.getProperty("java.io.tmpdir"), "mark").toFile();
+        int rnd = new Random().nextInt();
+        final File db = Paths.get(System.getProperty("java.io.tmpdir"), "mark" + rnd).toFile();
         if (db.exists())
             db.delete();
         try {