diff --git a/src/configure b/src/configure
index f9b48ae32c57f4ac5b73f6c8ce3190114dd4b2c0..2d683a15aaa1c6224e3d443235b98d6e8c4a8d1e 100755
--- a/src/configure
+++ b/src/configure
@@ -260,7 +260,7 @@ export ARMCI_SHR_BUF_METHOD=COPY
                 export MNH_ARCH=`echo $ARCH | grep LX`
                 export     ARCH=${MNH_ARCH:-LXifort}
                 export  VER_MPI=${VER_MPI:-MPIAUTO}
-                export OPTLEVEL=${OPTLEVEL:-O2}
+                export OPTLEVEL=${OPTLEVEL:-O3}
                 export MVWORK=${MVWORK:-NO}
 		export VER_CDF=${VER_CDF:-CDFAUTO}
                 export MNHENV=${MNHENV:-"