diff --git a/packer-image-buid.groovy b/packer-image-buid.groovy
index 32c499d..439f40a 100644
--- a/packer-image-buid.groovy
+++ b/packer-image-buid.groovy
@@ -47,13 +47,17 @@
 extra_vars = readYaml text: job_env.get('EXTRA_VARIABLES_YAML','').trim()
 // FIXME: os_openrc should be refactored.
 os_openrc = readYaml text: job_env.get('OPENSTACK_OPENRC_YAML','').trim()
-if (job_env.get('TIMESTAMP_INAME', false)) {
+if (job_env.get('TIMESTAMP_INAME', false).toBoolean()) {
   imageName = job_env.IMAGE_NAME + "-" + dateTime
 }else {
   imageName = job_env.IMAGE_NAME
 }
 // Overwrite IMAGE_NAME in template.json with expected
 extra_vars['IMAGE_NAME'] = imageName
+// Fix some variables
+job_env['CLEANUP_AFTER'] = job_env.CLEANUP_AFTER.toBoolean()
+job_env['SKIP_UPLOAD'] = job_env.SKIP_UPLOAD.toBoolean()
+job_env['CLEANUP_AFTER'] = job_env.CLEANUP_AFTER.toBoolean()
 job_env['BUILD_ONLY'] = job_env.BUILD_ONLY.toLowerCase()
 job_env['PUBLISH_BACKEND'] = job_env.PUBLISH_BACKEND.toLowerCase()
 //