diff --git a/lustre/tests/sanity-lmv.sh b/lustre/tests/sanity-lmv.sh
index 38d2a4d9054107aff93f26f480dfca01a91250ed..2eedda12593fb3db3e07657c6f9ed38ecff3e317 100644
--- a/lustre/tests/sanity-lmv.sh
+++ b/lustre/tests/sanity-lmv.sh
@@ -39,6 +39,7 @@ SOCKETSERVER=${SOCKETSERVER:-socketserver}
 SOCKETCLIENT=${SOCKETCLIENT:-socketclient}
 IOPENTEST1=${IOPENTEST1:-iopentest1}
 IOPENTEST2=${IOPENTEST2:-iopentest2}
+PTLDEBUG=${PTLDEBUG:-0}
 
 if [ $UID -ne 0 ]; then
 	RUNAS_ID="$UID"
@@ -95,7 +96,7 @@ run_one() {
 	if ! mount | grep -q $DIR; then
 		$START
 	fi
-	echo -1 >/proc/sys/portals/debug	
+	echo $PTLDEBUG >/proc/sys/portals/debug	
 	log "== test $1: $2"
 	export TESTNAME=test_$1
 	test_$1 || error "test_$1: exit with rc=$?"