diff --git a/contrib/db/libmdbx/CMakeLists.txt b/contrib/db/libmdbx/CMakeLists.txt
index 68ca42eb..452942bf 100644
--- a/contrib/db/libmdbx/CMakeLists.txt
+++ b/contrib/db/libmdbx/CMakeLists.txt
@@ -1,15 +1,13 @@
 
-set (mdbx_sources src/mdbx.c src/osal.c)
-
 if(WIN32)
   message(STATUS "MDBX locks: lck-windows.c")
-  set (mdbx_sources "${mdbx_sources} src/lck-windows.c")  
+  set (mdbx_sources src/mdbx.c src/lck-windows.c )
 elseif(APPLE)
   message(STATUS "MDBX locks: lck-posix.c")
-  set (mdbx_sources "${mdbx_sources} src/lck-posix.c")  
+  set (mdbx_sources src/mdbx.c src/lck-posix.c )
 else()
   message(STATUS "MDBX locks: lck-linux.c")
-  set (mdbx_sources "${mdbx_sources} src/lck-linux.c")  
+  set (mdbx_sources src/mdbx.c src/lck-linux.c )
 endif()