diff --git a/src/main/java/net/openhft/chronicle/map/CloseablesManager.java b/src/main/java/net/openhft/chronicle/map/CloseablesManager.java
index 0bc2d6ca8..adb89ed18 100644
--- a/src/main/java/net/openhft/chronicle/map/CloseablesManager.java
+++ b/src/main/java/net/openhft/chronicle/map/CloseablesManager.java
@@ -86,7 +86,7 @@ final class CloseablesManager implements Closeable {
     }
 
 
-    public boolean isEmpty() {
+    public synchronized boolean isEmpty() {
         return closeables.isEmpty();
     }
 }