diff --git a/lib/session-state.js b/lib/session-state.js
index 449ab669..efbd9af4 100644
--- a/lib/session-state.js
+++ b/lib/session-state.js
@@ -754,6 +754,11 @@ module.exports = class SessionState {
       tx.deleteBlockRange(treeLength, this.length)
     }
 
+    for (const root of roots) {
+      if (root !== null) tx.putTreeNode(root)
+    }
+
+    // no nodes will be copied in shallow mode
     for (const node of nodes) {
       if (node !== null) tx.putTreeNode(node)
     }