diff --git a/ChangeLog b/ChangeLog
index 191b16bd20..8fa42c34d9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jan 22 14:53:29 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* test/ruby/test_process.rb (MANDATORY_ENVS): needs RUBYLIB to run
+	  tests without install.
+
 Thu Jan 22 12:19:29 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* gc.c (define_final): cannot define finalizer for immediate
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index eda85c2e7f..8984caace1 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -199,7 +199,7 @@ class TestProcess < Test::Unit::TestCase
     }
   end
 
-  MANDATORY_ENVS = []
+  MANDATORY_ENVS = %w[RUBYLIB]
   if /linux/ =~ RbConfig::CONFIG['target_os']
     MANDATORY_ENVS << 'LD_PRELOAD'
   end