diff --git a/lib/execjs/module.rb b/lib/execjs/module.rb
index b89dc22..8cfb704 100644
--- a/lib/execjs/module.rb
+++ b/lib/execjs/module.rb
@@ -8,8 +8,6 @@ class ProgramError              < Error; end
   class RuntimeUnavailable < RuntimeError; end
 
   class << self
-    attr_reader :runtime
-
     def runtime=(runtime)
       raise RuntimeUnavailable, "#{runtime.name} is unavailable on this system" unless runtime.available?
       @runtime = runtime