diff --git a/lib/rb/lib/thrift/server.rb b/lib/rb/lib/thrift/server.rb
index 95258f0..62d210b 100644
--- a/lib/rb/lib/thrift/server.rb
+++ b/lib/rb/lib/thrift/server.rb
@@ -48,11 +48,9 @@
   deprecate_class! :TSimpleServer => SimpleServer
 end
 
-begin
-  require 'fastthread'
-rescue LoadError
-  require 'thread'
-end
+# do *not* use fastthread
+# it has a bug that triggers on NonblockingServer
+require 'thread'
 
 module Thrift
   class ThreadedServer < Server