diff --git a/CMakeLists.txt b/CMakeLists.txt
index 96d2ebeb00..e29c9dfd9c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -686,7 +686,7 @@ endif(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
                 link_libraries(${OPENMPI_LIBRARIES})
                 find_file(MpidotH mpi.h PATHS ${OPENMPI_INCLUDE_DIRS} NO_DEFAULT_PATH)
                 if(NOT MpidotH)
-                    message( FATAL_ERROR "mpi.h was not found. Check for error above.")
+                    message( WARNING "mpi.h was not found. Check for error above.")
                 endif()
             endif()
             find_package(MEDFile REQUIRED)