diff --git a/main.py b/main.py
index b7a75f1..47d7fc1 100755
--- a/main.py
+++ b/main.py
@@ -56,7 +56,7 @@ def generate_file(template, host_mac_ip, file_prefix):
 
         filename = path+'/generated/{file_prefix}{key}.list'.format(
                 key=key,
-                file_prefix=file_prefix)
+                file_prefix=file_prefix).lower().replace(" ", "_")
         with open(filename, 'w+') as f:
             f.write(dhcp_leases_content)