diff --git a/Modules/FindMPI.cmake b/Modules/FindMPI.cmake
index 250d8a6b3c..1be4ccfa7f 100644
--- a/Modules/FindMPI.cmake
+++ b/Modules/FindMPI.cmake
@@ -413,7 +413,7 @@ function (interrogate_mpi_compiler lang try_libs)
           HINTS         ${_MPI_BASE_DIR} ${_MPI_PREFIX_PATH}
           PATH_SUFFIXES lib)
         if (MPI_LIBRARIES_WORK AND MPI_LIB)
-          set(MPI_LIBRARIES_WORK "${MPI_LIBRARIES_WORK} ${MPI_LIB}")
+          list(APPEND MPI_LIBRARIES_WORK ${MPI_LIB})
         endif()
       endif()