diff --git a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
index 949ea3da7..3cd6572c4 100755
--- a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
+++ b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
@@ -2223,7 +2223,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         if (eventListener != null) {
                             eventListener.onPut(toKey.toInstance(copies, key, keySize),
                                     toValue.toInstance(copies, value, valueSize), null, false,
-                                    false);
+                                    prevValueSize == 0);
                         }
                     }
                 }