diff --git a/sit b/sit
index 2f6e92e..d40a8f4 100755
--- a/sit
+++ b/sit
@@ -20,7 +20,7 @@ source "$SIT_PATH/functions.sh"
 
 # compiler to use
 # (gnu|intel|pgi)
-COMPILER=${COMPILER:=gnu}
+COMPILER=${COMPILER:=system}
 # use specific compiler version
 COMPILER_VERSION=${COMPILER_VERSION:=}
 
@@ -29,19 +29,25 @@ COMPILER_VERSION=${COMPILER_VERSION:=}
 PACKAGE_DESCRIPTOR=${PACKAGE_DESCRIPTOR:+-$PACKAGE_DESCRIPTOR}
 
 
-
 # Compiler specifications
 
-if [ -z "$COMPILER_VERSION" ] ; then
-	COMPILER_MODULE=compiler/${COMPILER}
-else
-    COMPILER_MODULE=compiler/${COMPILER}/${COMPILER_VERSION}
+if [ "$COMPILER" == "system" ] ; then
+    echo "Using system default compiler"
+else 
+    if [ -z "$COMPILER_VERSION" ] ; then
+        COMPILER_MODULE=compiler/${COMPILER}
+    else
+        COMPILER_MODULE=compiler/${COMPILER}/${COMPILER_VERSION}
+    fi
+
+    echo "Loading compiler module ${COMPILER_MODULE}"
+    module load ${COMPILER_MODULE}
 fi
 
-echo "Loading compiler module ${COMPILER_MODULE}"
-module load ${COMPILER_MODULE}
-
 case ${COMPILER} in
+    system)
+        COMPILER=""   # prevent any compiler specs in the prefix
+        ;;
     gnu)
         COMPILER_OPTS="CC=gcc CXX=g++ FC=gfortran F77=gfortran"
         if [ "x${COMPILER_VERSION}" == "x" ] ; then
@@ -64,8 +70,11 @@ case ${COMPILER} in
         echo "Unknown compiler ${COMPILER}."
         ;;
 esac
+
 # make the compiler variables CC, CXX, FC and F77 available
-export ${COMPILER_OPTS}
+if [ ! -z $COMPILER_OPTS ] ; then  
+    export ${COMPILER_OPTS}
+fi
 
 if [ ! -z "$MPI" ] ; then 
     MPI_MODULE="mpi/$MPI"