diff --git a/lib/mutant/cli.rb b/lib/mutant/cli.rb
index 4aeea71d..e0a69e1f 100644
--- a/lib/mutant/cli.rb
+++ b/lib/mutant/cli.rb
@@ -192,7 +192,7 @@ module Mutant
     #
     # @api private
     def with(attributes)
-      @config = @config.with(attributes)
+      @config = config.with(attributes)
     end
 
     # Add configuration