diff --git a/sms_received.sh b/sms_received.sh
index 9b2ad32..323f58d 100755
--- a/sms_received.sh
+++ b/sms_received.sh
@@ -72,7 +72,7 @@ CMD=$(echo "$TEXT" | awk '{print toupper($1)}')
 # SWITCH CASE DEPENDING ON SMS TEXT FIRST WORD
 ########################################################################
 echo "COMMAND = $CMD"
-[[ "$CMD" == ""]] && exit 1
+[[ ! $CMD ]] && exit 1
 
 # Handle commands
 case "$CMD" in