diff --git a/agent/agent.sh b/agent/agent.sh
index 41b96f8..556571c 100644
--- a/agent/agent.sh
+++ b/agent/agent.sh
@@ -12,7 +12,8 @@ snore()
 
 function checkNMI {
 
-  local nmi=$(awk '/NMI/ {for (i=2; i<=NF; i++) if ($i ~ /^[0-9]+$/) {sum+=$i}} END {print sum}' /proc/interrupts)
+  local nmi
+  nmi=$(awk '/NMI/ {for (i=2; i<=NF; i++) if ($i ~ /^[0-9]+$/) {sum+=$i}} END {print sum}' /proc/interrupts)
 
   if [ "$nmi" != "" ] && [ "$nmi" -ne "0" ]; then