diff --git a/petrified b/petrified
index f8fb9d7..a92a156 100755
--- a/petrified
+++ b/petrified
@@ -199,7 +199,7 @@ fi
 if (( ${USE_PID} == 1 )); then
   PIDNUM=$(cat "${PET_PID}" 2>/dev/null)
   # check if we have a number
-  if [[ ${PIDMUM} =~ ^-?[0-9]+$ ]]; then
+  if [[ ${PIDNUM} =~ ^-?[0-9]+$ ]]; then
     kill -0 ${PIDNUM}
     if (( $? == 0 )); then
       logmsg "Detected a running process ${PIDNUM}, exiting."