diff --git a/libqpdf/NNTree.cc b/libqpdf/NNTree.cc
index ee5ba25..1ee7f16 100644
--- a/libqpdf/NNTree.cc
+++ b/libqpdf/NNTree.cc
@@ -64,7 +64,7 @@ NNTreeIterator::updateIValue(bool allow_invalid)
         return;
     }
 
-    if (item_number < 0 || !node.isDictionary()) {
+    if (item_number < 0 || !node) {
         if (!allow_invalid) {
             throw std::logic_error(
                 "attempt made to dereference an invalid name/number tree iterator");
@@ -74,12 +74,6 @@ NNTreeIterator::updateIValue(bool allow_invalid)
     impl.error(node, "update ivalue: items array is too short");
 }
 
-NNTreeIterator::PathElement::PathElement(QPDFObjectHandle const& node, int kid_number) :
-    node(node),
-    kid_number(kid_number)
-{
-}
-
 Dictionary
 NNTreeIterator::getNextKid(PathElement& pe, bool backward)
 {
@@ -349,7 +343,7 @@ NNTreeIterator::insertAfter(QPDFObjectHandle const& key, QPDFObjectHandle const&
         return;
     }
 
-    Array items = node.getKey(impl.itemsKey());
+    Array items = node[impl.itemsKey()];
     if (!items) {
         impl.error(node, "node contains no items array");
     }
@@ -451,7 +445,7 @@ NNTreeIterator::remove()
 
         if (parent == path.end()) {
             // We erased the very last item. Convert the root to an empty items array.
-            element->node.removeKey("/Kids");
+            element->node.erase("/Kids");
             element->node.replaceKey(impl.itemsKey(), Array::empty());
             path.clear();
             setItemNumber(impl.tree_root, -1);
diff --git a/libqpdf/qpdf/NNTree.hh b/libqpdf/qpdf/NNTree.hh
index afc45ee..084e6da 100644
--- a/libqpdf/qpdf/NNTree.hh
+++ b/libqpdf/qpdf/NNTree.hh
@@ -81,9 +81,13 @@ class NNTreeIterator final
     class PathElement
     {
       public:
-        PathElement(QPDFObjectHandle const& node, int kid_number);
+        PathElement(qpdf::Dictionary const& node, int kid_number) :
+            node(node),
+            kid_number(kid_number)
+        {
+        }
 
-        QPDFObjectHandle node;
+        qpdf::Dictionary node;
         int kid_number;
     };
 
@@ -114,7 +118,7 @@ class NNTreeIterator final
 
     NNTreeImpl& impl;
     std::list<PathElement> path;
-    QPDFObjectHandle node;
+    qpdf::Dictionary node;
     int item_number{-1};
     value_type ivalue;
 };