diff --git a/src/ripple/shamap/impl/SHAMap.cpp b/src/ripple/shamap/impl/SHAMap.cpp
index 9d69fe951a..4e5911f4f7 100644
--- a/src/ripple/shamap/impl/SHAMap.cpp
+++ b/src/ripple/shamap/impl/SHAMap.cpp
@@ -74,7 +74,8 @@ SHAMap::snapShot (bool isMutable) const
     newMap.root_ = root_;
     newMap.backed_ = backed_;
 
-    if ((state_ != SHAMapState::Immutable) || !isMutable)
+    if ((state_ != SHAMapState::Immutable) ||
+        (newMap.state_ != SHAMapState::Immutable))
     {
         // If either map may change, they cannot share nodes
         newMap.unshare ();