diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 5b590525..bb9b511d 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -3010,7 +3010,7 @@ QPDF::findAttachmentStreams()
     {
         return;
     }
-    QPDFNameTreeObjectHelper ef_tree(embedded_files);
+    QPDFNameTreeObjectHelper ef_tree(embedded_files, *this);
     for (auto i: ef_tree)
     {
         QPDFObjectHandle item = i.second;
diff --git a/libtests/nntree.cc b/libtests/nntree.cc
index 7ef069c3..1579ab46 100644
--- a/libtests/nntree.cc
+++ b/libtests/nntree.cc
@@ -6,9 +6,9 @@
 
 static bool any_failures = false;
 
-bool report(QPDFObjectHandle oh, long long item, long long exp_item)
+bool report(QPDF& q, QPDFObjectHandle oh, long long item, long long exp_item)
 {
-    QPDFNumberTreeObjectHelper nh(oh);
+    QPDFNumberTreeObjectHelper nh(oh, q);
     QPDFObjectHandle o1;
     long long offset = 0;
     bool f1 = nh.findObjectAtOrBelow(item, o1, offset);
@@ -81,8 +81,8 @@ void test_bsearch()
         return node;
     };
 
-    auto r = [](QPDFObjectHandle& oh, int item, int exp) {
-        if (report(oh, item, exp))
+    auto r = [&q](QPDFObjectHandle& oh, int item, int exp) {
+        if (report(q, oh, item, exp))
         {
             any_failures = true;
         }
@@ -218,7 +218,7 @@ void test_depth()
                           .getArrayItem(1));
     }
 
-    QPDFNameTreeObjectHelper nh(n0);
+    QPDFNameTreeObjectHelper nh(n0, q);
     std::cout << "--- forward ---" << std::endl;
     for (auto i: nh)
     {
diff --git a/qpdf/test_driver.cc b/qpdf/test_driver.cc
index 62e8a5ea..c174c2fe 100644
--- a/qpdf/test_driver.cc
+++ b/qpdf/test_driver.cc
@@ -1748,7 +1748,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         // Test number tree. This test is crafted to work with
         // number-tree.pdf
         QPDFObjectHandle qtest = pdf.getTrailer().getKey("/QTest");
-        QPDFNumberTreeObjectHelper ntoh(qtest);
+        QPDFNumberTreeObjectHelper ntoh(qtest, pdf);
         for (auto iter: ntoh)
         {
             std::cout << iter.first << " "
@@ -1806,7 +1806,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         // Test name tree. This test is crafted to work with
         // name-tree.pdf
         QPDFObjectHandle qtest = pdf.getTrailer().getKey("/QTest");
-        QPDFNameTreeObjectHelper ntoh(qtest);
+        QPDFNameTreeObjectHelper ntoh(qtest, pdf);
         for (auto iter: ntoh)
         {
             std::cout << iter.first << " -> "