diff --git a/lib/process_shared.rb b/lib/process_shared.rb
index 6b1e8bb..2f1b184 100644
--- a/lib/process_shared.rb
+++ b/lib/process_shared.rb
@@ -1,6 +1,6 @@
 require 'ffi'
 
-if VERSION =~ /^1.8/
+if RUBY_VERSION =~ /^1.8/
   require 'process_shared/define_singleton_method'
   
   module ProcessShared
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 7ae810f..5a24791 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,4 +1,4 @@
-require 'rubygems' if VERSION =~ /^1.8/
+require 'rubygems' if RUBY_VERSION =~ /^1.8/
 gem 'minitest'
 require 'minitest/spec'
 require 'minitest/autorun'