diff --git a/prodtests/full_system_test.sh b/prodtests/full_system_test.sh
index c0195adb1bcc9..96a4ed9c81182 100755
--- a/prodtests/full_system_test.sh
+++ b/prodtests/full_system_test.sh
@@ -222,7 +222,7 @@ if [[ $BEAMTYPE == "PbPb" ]] && [ $NEvents -ge 5 ] ; then
   CHECK_DETECTORS_RAW+=" EMC PHS HMP"
 fi
 for i in $CHECK_DETECTORS_RAW; do
-  if [[ `ls -l raw/$i/*.raw | awk '{print $5}' | grep -v "^0\$" | wc -l` == "0" ]]; then
+  if [[ `ls -l raw/$i/*.raw | awk '{print $5}' | grep -c -v "^0\$"` == "0" ]]; then
     echo "ERROR: Full system test did generate no raw data for $i"
     exit 1
   fi