diff --git a/mdbx.h++ b/mdbx.h++
index 385bf9a2..d4cd7077 100644
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -558,6 +558,7 @@ MDBX_DECLARE_EXCEPTION(something_busy);
 MDBX_DECLARE_EXCEPTION(thread_mismatch);
 MDBX_DECLARE_EXCEPTION(transaction_full);
 MDBX_DECLARE_EXCEPTION(transaction_overlapping);
+MDBX_DECLARE_EXCEPTION(duplicated_lck_file);
 #undef MDBX_DECLARE_EXCEPTION
 
 [[noreturn]] LIBMDBX_API void throw_too_small_target_buffer();
diff --git a/src/mdbx.c++ b/src/mdbx.c++
index 9ac0d8d5..9ac6cd71 100644
--- a/src/mdbx.c++
+++ b/src/mdbx.c++
@@ -285,7 +285,7 @@ DEFINE_EXCEPTION(something_busy)
 DEFINE_EXCEPTION(thread_mismatch)
 DEFINE_EXCEPTION(transaction_full)
 DEFINE_EXCEPTION(transaction_overlapping)
-
+DEFINE_EXCEPTION(duplicated_lck_file)
 #undef DEFINE_EXCEPTION
 
 __cold const char *error::what() const noexcept {
@@ -371,6 +371,7 @@ __cold void error::throw_exception() const {
     CASE_EXCEPTION(thread_mismatch, MDBX_THREAD_MISMATCH);
     CASE_EXCEPTION(transaction_full, MDBX_TXN_FULL);
     CASE_EXCEPTION(transaction_overlapping, MDBX_TXN_OVERLAPPING);
+    CASE_EXCEPTION(duplicated_lck_file, MDBX_DUPLICATED_CLK);
 #undef CASE_EXCEPTION
   default:
     if (is_mdbx_error())