diff --git a/src/test/java/net/openhft/chronicle/map/CHMUseCasesTest.java b/src/test/java/net/openhft/chronicle/map/CHMUseCasesTest.java
index d8f548666..da2fa09ca 100644
--- a/src/test/java/net/openhft/chronicle/map/CHMUseCasesTest.java
+++ b/src/test/java/net/openhft/chronicle/map/CHMUseCasesTest.java
@@ -231,7 +231,8 @@ public class CHMUseCasesTest {
                 return map1;
 
             case SIMPLE_PERSISTED:
-                final File file = new File(TMP + "/chronicle-map-" + System.nanoTime() + ".map");
+                final File file = new File(TMP + "/chronicle-map-" + System.nanoTime() +
+                        System.currentTimeMillis() + ".map");
                 file.deleteOnExit();
                 map1 = builder.createPersistedTo(file);
                 closeables.add(map1);
@@ -2857,4 +2858,4 @@ interface IBean {
         void setMessage(@MaxSize(20) String px);
 
     }
-}
\ No newline at end of file
+}