diff --git a/testing/install/CXX11/CMakeLists.txt b/testing/install/CXX11/CMakeLists.txt
index 9f4e54f816..7a01b6b252 100644
--- a/testing/install/CXX11/CMakeLists.txt
+++ b/testing/install/CXX11/CMakeLists.txt
@@ -4,7 +4,7 @@
 #------------------------------------------------------------------------------#
 
 cmake_minimum_required(VERSION 3.6)
-project(adios_cxx11_test LANGUAGES C CXX)
+project(adios_cxx11_test CXX)
 enable_testing()
 
 find_package(adios2 REQUIRED)
@@ -15,9 +15,12 @@ target_link_libraries(adios_cxx11_test adios2::cxx11)
 add_test(NAME adios_cxx11_test COMMAND adios_cxx11_test)
 
 if(ADIOS2_HAVE_MPI)
+  # Avoid using MPI::MPI_CXX
+  enable_language(C)
+
   find_package(MPI REQUIRED)
-  set(src main_mpi.cxx)
   set(mpilib MPI::MPI_C)
+  set(src main_mpi.cxx)
   set(mpiexec ${MPIEXEC_EXECUTABLE} ${MPIEXEC_EXTRA_FLAGS})
   add_compile_definitions(OMPI_SKIP_MPICXX MPICH_SKIP_MPICXX)