diff --git a/mdbx.h++ b/mdbx.h++
index dcdb3303..c1b29a26 100644
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -2679,6 +2679,7 @@ public:
 
 LIBMDBX_API ::std::ostream &operator<<(::std::ostream &, const slice &);
 LIBMDBX_API ::std::ostream &operator<<(::std::ostream &, const pair &);
+LIBMDBX_API ::std::ostream &operator<<(::std::ostream &, const pair_result &);
 template <class ALLOCATOR>
 inline ::std::ostream &operator<<(::std::ostream &out,
                                   const buffer<ALLOCATOR> &it) {
diff --git a/src/mdbx.c++ b/src/mdbx.c++
index f21deaa0..6f3f2e30 100644
--- a/src/mdbx.c++
+++ b/src/mdbx.c++
@@ -1297,6 +1297,11 @@ __cold ::std::ostream &operator<<(::std::ostream &out, const pair &it) {
   return out << "{" << it.key << " => " << it.value << "}";
 }
 
+__cold ::std::ostream &operator<<(::std::ostream &out, const pair_result &it) {
+  return out << "{" << (it.done ? "done: " : "non-done: ") << it.key << " => "
+             << it.value << "}";
+}
+
 __cold ::std::ostream &operator<<(::std::ostream &out,
                                   const ::mdbx::env::geometry::size &it) {
   switch (it.bytes) {