diff --git a/lib/customerio/client.rb b/lib/customerio/client.rb
index d322ff4..e49a6cc 100644
--- a/lib/customerio/client.rb
+++ b/lib/customerio/client.rb
@@ -155,7 +155,7 @@ def create_or_update(attributes = {})
         raise MissingIdAttributeError.new("Must provide a customer id")
       end
 
-      # Use cio_id as the identifier, as present,
+      # Use cio_id as the identifier, if present,
       # to allow the id and email identifiers to be updated.
       customer_id = attributes[:id]
       if !is_empty?(attributes[:cio_id])