diff --git a/lib/vmpooler.rb b/lib/vmpooler.rb
index 28aa323..5679087 100644
--- a/lib/vmpooler.rb
+++ b/lib/vmpooler.rb
@@ -63,6 +63,7 @@ module Vmpooler
     parsed_config[:config]['migration_limit'] = string_to_int(ENV['MIGRATION_LIMIT']) if ENV['MIGRATION_LIMIT']
     parsed_config[:config]['vm_checktime'] = string_to_int(ENV['VM_CHECKTIME']) || parsed_config[:config]['vm_checktime'] || 1
     parsed_config[:config]['vm_lifetime'] = string_to_int(ENV['VM_LIFETIME']) || parsed_config[:config]['vm_lifetime'] || 24
+    parsed_config[:config]['max_lifetime_upper_limit'] = string_to_int(ENV['MAX_LIFETIME_UPPER_LIMIT']) || string_to_int(parsed_config[:config]['max_lifetime_upper_limit'])
     parsed_config[:config]['ready_ttl'] = string_to_int(ENV['READY_TTL']) || parsed_config[:config]['ready_ttl'] || 5
     parsed_config[:config]['ondemand_request_ttl'] = string_to_int(ENV['ONDEMAND_REQUEST_TTL']) || parsed_config[:config]['ondemand_request_ttl'] || 5
     parsed_config[:config]['prefix'] = ENV['PREFIX'] || parsed_config[:config]['prefix'] || ''