diff --git a/startup.sh b/startup.sh
old mode 100644
new mode 100755
index 117157e..c20f536
--- a/startup.sh
+++ b/startup.sh
@@ -24,6 +24,11 @@ case "${NETWORK}" in
     ;;
 esac
 
+# Am I on ec2 instances?
+if [[ ${zone} == "unknown" ]]; then
+  zone=$(curl -m2 -s http://169.254.169.254/latest/dynamic/instance-identity/document | jq -r '.availabilityZone' | cut -f3 -d-)
+fi
+
 export CODE_HASH="$(cat code_hash.txt)"
 export AZ="${IP} in AZ-${zone}"