diff --git a/cookbooks/aws-parallelcluster-platform/files/isolated/iso-ca-bundle-config.sh b/cookbooks/aws-parallelcluster-platform/files/isolated/iso-ca-bundle-config.sh
index 991daa72f..c72732b7b 100644
--- a/cookbooks/aws-parallelcluster-platform/files/isolated/iso-ca-bundle-config.sh
+++ b/cookbooks/aws-parallelcluster-platform/files/isolated/iso-ca-bundle-config.sh
@@ -2,7 +2,8 @@
 set -ex
 
 function get_instance_region {
-  local _token=$(curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 3600")
+  local _token
+  _token=$(curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 3600")
   curl -H "X-aws-ec2-metadata-token: $_token" -v "http://169.254.169.254/latest/meta-data/placement/region" 2> /dev/null
 }