diff --git a/btree.cpp b/btree.cpp
index 31c212a..a49237f 100644
--- a/btree.cpp
+++ b/btree.cpp
@@ -141,6 +141,17 @@
 } // bTree::getKeys
 
 void
+bTree::setRoot(uPtr value) {
+  info->root = value;
+
+  if (!memoryTree) {
+    if (!vfs->fSeek((int)&info->root - (int)info)) exit(42);
+    if (!vfs->fWrite(&info->root, sizeof(info->root))) exit(42);
+  } // if not memoryTree
+  return;
+} // bTree::setRoot
+
+void
 bTree::setNull(uPtr & u) {
   u.offset = 0;
 } // bTree::setNull
diff --git a/btree.h b/btree.h
index b17c25f..2ac268e 100644
--- a/btree.h
+++ b/btree.h
@@ -27,6 +27,7 @@
   void     setNodes(uInt32);
   void     setHeight(uInt32);
   void     setKeys(uInt32);
+  void     setRoot(uPtr);
   void     setNull(uPtr &);
  public:
            bTree(char *, uInt32, treeTypes, bTreeVFS *);