diff --git a/add-log-retention.js b/add-log-retention.js
index 7e90c2b..e138f02 100644
--- a/add-log-retention.js
+++ b/add-log-retention.js
@@ -35,7 +35,9 @@ class AwsAddLogRetention {
       return;
     }
 
-    const resources = nco(service.resources, {});
+    service.resources = nco(service.resources, {});
+
+    const resources = service.resources;
     resources.Resources = nco(resources.Resources, {});
 
     Object.keys(service.functions).forEach(functionName => {