Index: lib/ruby/1.8/erb.rb
===================================================================
--- lib/ruby/1.8/erb.rb	(revision 8342)
+++ lib/ruby/1.8/erb.rb	(working copy)
@@ -705,16 +705,16 @@
   # setup of an ERB _compiler_ object.
   #
   def set_eoutvar(compiler, eoutvar = '_erbout')
-    compiler.put_cmd = "#{eoutvar}.concat"
-    compiler.insert_cmd = "#{eoutvar}.concat"
+    compiler.put_cmd = "#{eoutvar} << "
+    compiler.insert_cmd = "#{eoutvar} << "
 
     cmd = []
-    cmd.push "#{eoutvar} = ''"
+    cmd.push "#{eoutvar} = []"
     
     compiler.pre_cmd = cmd
 
     cmd = []
-    cmd.push(eoutvar)
+    cmd.push("#{eoutvar}.join('')")
 
     compiler.post_cmd = cmd
   end