diff --git a/cmake/SuperBuild.cmake b/cmake/SuperBuild.cmake
index 06174b10..6a58c2fe 100644
--- a/cmake/SuperBuild.cmake
+++ b/cmake/SuperBuild.cmake
@@ -101,11 +101,16 @@ endif(USE_GUI)
 #######################################################################
 if(USE_MPI)
   if(UNIX)
-    find_package(METIS QUIET)
-    if(NOT METIS_FOUND)
-      message(STATUS "Could not find METIS, it will be built from source")
-      include(cmake/external_projects/metis.cmake)
-    endif()
+    if (METIS_DIR)
+      message(STATUS "Using external METIS at: ${METIS_DIR}")
+    else (METIS_DIR)
+      message(STATUS "Looking for system METIS")
+      find_package(METIS QUIET)
+      if(NOT METIS_FOUND)
+	message(WARNING "Could not find METIS, it will be built from source (this might conflict with NGSolve MUMPS)!")
+	include(cmake/external_projects/metis.cmake)
+      endif(NOT METIS_FOUND)
+    endif(METIS_DIR)
   else(UNIX)
     find_package(METIS REQUIRED)
   endif(UNIX)