diff --git a/ChangeLog b/ChangeLog
index 1a9e2553e5..fd6651ee20 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jan 31 14:45:47 2011  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
+
+	* lib/irb/locale.rb (IRB::Locale::#search_file):
+	  Gem might be undefined if --disable-gems. [ruby-core:34990]
+
 Mon Jan 31 12:26:14 2011  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* addr2line.c: suppressed shorten-64-to-32 warnings.
diff --git a/lib/irb/locale.rb b/lib/irb/locale.rb
index 142b9a5951..77cc06ed30 100644
--- a/lib/irb/locale.rb
+++ b/lib/irb/locale.rb
@@ -147,7 +147,7 @@ module IRB
           full_path = File.join(libpath, lc_path)
           return full_path if File.readable?(full_path)
         end
-        redo if Gem.try_activate(lc_path)
+        redo if defined?(Gem) and Gem.try_activate(lc_path)
       end
       nil
     end