diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 6c446bdb1b..7269fc5c9b 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -245,13 +245,14 @@ else()
 endif()
 
 if(BUILD_MPI)
+  # do not include the (obsolete) MPI C++ bindings which makes
+  # for leaner object files and avoids namespace conflicts
+  set(MPI_CXX_SKIP_MPICXX TRUE)
   # We use a non-standard procedure to cross-compile with MPI on Windows
   if((CMAKE_SYSTEM_NAME STREQUAL "Windows") AND CMAKE_CROSSCOMPILING)
-    set(MPI_CXX_SKIP_MPICXX TRUE)
     include(MPI4WIN)
     target_link_libraries(lammps PUBLIC MPI::MPI_CXX)
   else()
-    set(MPI_CXX_SKIP_MPICXX TRUE)
     find_package(MPI REQUIRED)
     target_link_libraries(lammps PUBLIC MPI::MPI_CXX)
     option(LAMMPS_LONGLONG_TO_LONG "Workaround if your system or MPI version does not recognize 'long long' data types" OFF)