diff --git a/bin/run-cpu-stress.sh b/bin/run-cpu-stress.sh
index d947afd..156874c 100755
--- a/bin/run-cpu-stress.sh
+++ b/bin/run-cpu-stress.sh
@@ -10,6 +10,11 @@ else
  export THERMAL_ZONE=/sys/class/thermal/thermal_zone0/temp
 fi
 
+if [ -z "${1}" ]; then
+  echo "usage run-cpu-stress.sh <logfile>"
+  exit 1
+fi
+
 measure_temp.sh > ${1} &
 TPID=$!
 fio ${PISTRESS_HOME}/fio/fio_cpu