diff --git a/lib/mini_racer.rb b/lib/mini_racer.rb
index 400012b..f2b84dd 100644
--- a/lib/mini_racer.rb
+++ b/lib/mini_racer.rb
@@ -150,7 +150,6 @@ def initialize(max_memory: nil, timeout: nil, cputime_limit: nil, isolate: nil,
 
       @functions = {}
       @timeout = nil
-      @cputime_limit = nil
       @max_memory = nil
       @current_exception = nil
       @timeout = timeout