diff --git a/MPI/boost/modulefile b/MPI/boost/modulefile
index 992ec8f..27003ac 100644
--- a/MPI/boost/modulefile
+++ b/MPI/boost/modulefile
@@ -12,3 +12,4 @@ testing. It contains over eighty individual libraries.
 (Wikipedia)
 "
 
+setenv BOOST_ROOT "$PREFIX"