diff --git a/include/qpdf/QPDFNameTreeObjectHelper.hh b/include/qpdf/QPDFNameTreeObjectHelper.hh
index cc6ad0d..6bed9f0 100644
--- a/include/qpdf/QPDFNameTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNameTreeObjectHelper.hh
@@ -55,7 +55,7 @@ class QPDFNameTreeObjectHelper: public QPDFObjectHelper
     // QPDFNameTreeObjectHelper constructed in this way can't be
     // modified or repaired and will silently ignore problems in the
     // structure.
-    [[deprecated]]
+    [[deprecated("use constructor that takes QPDF&")]]
     QPDF_DLL
     QPDFNameTreeObjectHelper(QPDFObjectHandle);
 
diff --git a/include/qpdf/QPDFNumberTreeObjectHelper.hh b/include/qpdf/QPDFNumberTreeObjectHelper.hh
index 4a3b4f9..91682d8 100644
--- a/include/qpdf/QPDFNumberTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNumberTreeObjectHelper.hh
@@ -52,7 +52,7 @@ class QPDFNumberTreeObjectHelper: public QPDFObjectHelper
     // QPDFNumberTreeObjectHelper constructed in this way can't be
     // modified or repaired and will silently ignore problems in the
     // structure.
-    [[deprecated]]
+    [[deprecated("use constructor that takes QPDF&")]]
     QPDF_DLL
     QPDFNumberTreeObjectHelper(QPDFObjectHandle);